Process for preparing imidazodiazepines

ABSTRACT

Imidazodiazepine derivatives of the formula ##STR1## wherein A together with the two carbon atoms denoted as α and β is selected from the group consisting of ##STR2## the dotted line represents the double bond present in groups (a) and (b), D is &gt;C═O or &gt;C═S, R 1  is selected from the group consisting of cyano, lower alkanoyl and a group of the formula --COOR 4 , R 4  is selected from the group consisting of methyl, ethyl, isopropyl and 2-hydroxyethyl, R 5  is selected from the group consisting of hydrogen, trifluoromethyl and halogen and R 6  is selected from the group consisting of hydrogen, trifluoromethyl, halogen and lower alkyl and either R 2  is hydrogen and R 3  is hydrogen or lower alkyl or R 2  and R 3  together are trimethylene or propenylene and the carbon atom denoted as γ has the S- or R,S-configuration, 
     and pharmaceutically acceptable salts thereof are presented and have utility for antagonizing the central-depressant, muscle relaxant, ataxic, blood pressure-lowering and respiratory-depressant properties of 1,4-benzodiazepines which have tranquilizing activity. They can be used, for example, as antidotes in the case of intoxications in which excessive intake of 1,4-benzodiazepines which have tranquilizing participates, or for shortening an anaesthesia induced by such 1,4-benzodiazepines. They can also be used for suppressing the activities on the central nervous system of 1,4-benzodiazepines used in other fields of indication, for example of schistosomicidally-active 1,4-benzodiazepines such as (+)-5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2-one. 
     Also presented are processes to produce the imidazodiazepine derivatives and intermediates therefor.

This is a division of application Ser. No. 193,775 filed Oct. 3, 1980,now U.S. Pat. No. 4,316,839.

DESCRIPTION OF THE INVENTION

The present invention relates to imidazodiazepine derivatives. Moreparticularly, the invention is concerned withimidazo[1,5-a][1,4]diazepine derivatives of the formula ##STR3## whereinA together with the two carbon atoms denoted as α and β is selected fromthe group consisting of ##STR4## the dotted line represents the doublebond present in groups (a) and (b), D is >C═O or >C═S, R¹ is selectedfrom the group consisting of cyano, lower alkanoyl and a group of theformula --COOR⁴, R⁴ is selected from the group consisting of methyl,ethyl, isopropyl and 2-hydroxyethyl, R⁵ is selected from the groupconsisting of hydrogen, trifluoromethyl and halogen and R⁶ is selectedfrom the group consisting of hydrogen, trifluoromethyl, halogen andlower alkyl and either R² is hydrogen and R³ is hydrogen or lower alkylor R² and R³ together are trimethylene or propenylene and the carbonatom denoted as γ has the S- or R,S-configuration, and pharmaceuticallyacceptable acid addition salts thereof.

The aforementioned compounds are novel and possess valuablepharmacodynamic properties.

Objects of the present invention are compounds of formula I andpharmaceutically acceptable acid addition salts thereof per se and aspharmaceutically active substances, the manufacture of these compoundsand intermediates in the manufacture of these compounds, medicamentscontaining a compound of formula I or a pharmaceutically acceptable acidaddition salt thereof and the manufacture of such medicaments, as wellas the use of compounds of formula I or of pharmaceutically acceptableacid addition salts thereof in the control or prevention of illnesses.

As used herein, the term "lower alkyl" denotes a straight-chain orbranched-chain saturated hydrocarbon group containing at most 7,preferably at most 4, carbon atoms such as methyl, ethyl, n-propyl,isopropyl, n-butyl, sec.butyl, tert.butyl and the like. The term "loweralkanoyl" embraces groups such as acetyl, propionyl, butanoyl,sec.butanoyl and the like. The term "halogen" means fluorine, chlorine,bromine and iodine.

R¹ preferably represents cyano or a group of the formula --COOR⁴ inwhich R⁴ preferably represents methyl, ethyl or isopropyl.

When R² represents hydrogen, then R³ preferably represents methyl. WhenR² and R³ together represent trimethylene, then the carbon atom denotedby γ in formula I preferably has the S-configuration.

The symbol A preferably represents the group (a) hereinbefore with thedotted line signifying the double bond present in this group. In group(a), R⁵ preferably represents hydrogen or fluorine and R⁶ preferablyrepresents hydrogen, fluorine, chlorine or methyl with at least one ofR⁵ and R⁶ preferably representing hydrogen.

A particularly preferred compound of formula I is ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate.

Compounds of formula I which are especially preferred are:

Ethyl7-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

ethyl7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

ethyl(S)-8-chloro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,

ethyl(R,S)-11,13a-dihydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateand

ethyl(R,S)-8-fluoro-11,13a-dihydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate.

Other preferred compounds of formula I are:

Ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

methyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

isopropyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

methyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

isopropyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

ethyl5,6-dihydro-5,7-dimethyl-6-oxo-4H-imidazo-[1,5-a][1,4]benzodiazepine-3-carboxylate.

ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,

methyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,

isopropyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,

ethyl(S)-7-fluoro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,

ethyl(S)-11,12,13,13a-tetrahydro-8-methyl-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,

ethyl5,6-dihydro-5-methyl-6-thioxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

ethyl8-fluoro-5,6-dihydro-5-methyl-6-thioxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carbonitrile,

(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carbonitrile,

5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carbonitrile,

methyl(S)-10,11,12,12a-tetrahydro-8-oxo-8H-imidazo[5,1-c]pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-1-carboxylate,

ethyl(S)-10,11,12,12a-tetrahydro-8-oxo-8H-imidazo[5,1-c]pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-1-carboxylate,

ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a]thieno[2,3-f][1,4]diazepine-3-carboxylateand

methyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a]thieno[2,3-f][1,4]diazepine-3-carboxylate.

The following compounds are also representative compounds of formula I:

4,5-Dihydro-5-methyl-3-propionyl-6H-imidazo[1,5-a][1,4]benzodiazepine-6-one

ethyl5,6-dihydro-6-oxo-4H-imidazo[1,5-a][1,4]-benzodiazepine-3-carboxylate,

ethyl8-fluoro-5,6-dihydro-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

ethyl8-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

ethyl8-bromo-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]-benzodiazepine-3-carboxylate,

ethyl(S)-(+)-7-chloro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,

ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a]thieno[3,4-f][1,4]diazepine-3-carboxylate,

(2-hydroxyethyl)5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

(2-hydroxyethyl)8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

(2-hydroxyethyl)(S)-10,11,12,12a-tetrahydro-8-oxo-8H-imidazo[5,1-c]pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-1-carboxylate,

ethyl(R,S)-13,13a-dihydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,

ethyl5,6-dihydro-5-methyl-8-trifluoromethyl-6-oxo-4H-imidazo[1,5-a]1,4]benzodiazepine-3-carboxylate,

ethyl5,6-dihydro-5-methyl-7-trifluoromethyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,

ethyl7-chloro-5,6-dihydro-8-fluoro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateand

ethyl(S)-8-chloro-7-fluoro-9-oxo-9H-11,12,13,13a-tetrahydro-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate.

The imidazo[1,5-a][1,4]diazepines of formula I hereinbefore and theirpharmaceutically acceptable acid addition salts can be manufactured inaccordance with the present invention by

(a) reacting a compound of the general formula ##STR5## wherein A andthe dotted line have the significance given earlier, X is a leavinggroup and either R²¹ is hydrogen and R³¹ is lower alkyl or R²¹ and R³¹together are trimethylene or propenylene and the carbon atom denoted asγ has the S- or R,S-configuration,

in the presence of a base with an isocyanoacetic ester of the generalformula

    CN--CH.sub.2 --COOR.sup.41                                 III

wherein R⁴¹ represents methyl, ethyl or isopropyl, or

(b) treating a compound of the general formula ##STR6## wherein A, thedotted line, R²¹, R³¹ and R⁴¹ have the significance given earlier,

with a formylating agent, or

(c) dehydrogenating a compound of the general formula ##STR7## whereinA, the dotted line, R²¹, R³¹ and R⁴¹ have the significance givenearlier, or

(d) converting the carboxamido group in a compound of the generalformula ##STR8## wherein A, the dotted line, D, R²¹ and R³¹ have thesignificance given earlier,

into the nitrile group, or

(e) appropriately substituting a compound of the general formula##STR9## wherein A, the dotted line, D and R¹ have the significancegiven earlier,

at the secondary amino group, or

(f) cleaving off the protecting group in a compound of the generalformula ##STR10## wherein A, the dotted line, D and R¹ have thesignificance given earlier, and Z represents a protecting group, or

(g) converting the oxime group in a compound of the general formula##STR11## wherein A, the dotted line, D, R² and R³ have the significancegiven earlier,

into the nitrile group, or

(h) converting the hydroxyl group in a compound of the general formula##STR12## wherein A, the dotted line, D, R² and R³ have the significancegiven earlier and R⁷ is lower alkyl,

into the keto group, or

(i) trans-esterifying a compound of the general formula ##STR13##wherein A, the dotted line, D, R², R³ and R⁷ have the significance givenearlier, or

(j) converting the carbonyl group in a compound of the general formula##STR14## wherein R¹¹ is a cyano or a group of the formula --COOR⁴ andA, the dotted line, R², R³ and R⁴ have the significance given earlier,

into the thiocarbonyl group, and

(k) if desired, converting a compound of formula I into apharmaceutically acceptable acid addition salt.

In accordance with embodiment (a) of the process, compounds of formula Ican be manufactured from compounds of formula II and isocyanoaceticesters of formula III. The leaving group denoted by the symbol X informula II is, for example, a readily cleavable phosphinyl group, e.g. agroup of the formula ##STR15## wherein R⁴ represents lower alkyl and R⁵and R⁶ each represent lower alkyl, allyl, phenyl or substituted phenylor R⁵ and R⁶ together with the nitrogen atom represent an unsubstitutedor substituted heterocyclic ring with 3-8 members (e.g. morpholine),

a halogen atom, an alkylthio group, an aralkylthio group, anN-nitrosoalkylamino group, an alkoxy group, a mercapto group and thelike (when X represents a mercapto group, then the correspondingcompound of formula II is the iminothiol form of the correspondingthiolactam). The reaction of a compound of formula II with anisocyanoacetic ester of formula III is carried out in an inert solventsuch as dimethylformamide, hexamethylphosphoric acid triamide, dimethylsulphoxide, tetrahydrofuran or any other suitable inert organic solventand in the presence of a base which is sufficiently strongly basic toform the anion of the isocyanoacetic ester of formula III. Suitablebases are alkali metal alkoxides such as sodium methoxide or potassiumtert.butoxide, alkali metal hydrides such as sodium hydride, alkalimetal amides such as lithium amide or lithium diisopropylamide, tertiaryamines such as triethylamine, and the like. The reaction is convenientlycarried out at a temperature between about -40° C. and about roomtemperature.

In accordance with embodiment (b) of the process, compounds of formula Ican be manufactured by treating a compound of formula IV with aformylating agent. Suitable formylating agents for this embodiment ofthe process are lower alkyl esters of orthoformic acid and technicalequivalents thereof, for example orthoamides such asN,N-dimethylformamide dimethyl acetal,N,N,N',N',N",N"-hexamethylmethanetriamine and the like. The reaction ofa compound of formula IV with a formylating agent is convenientlycarried out in the presence of an acid catalyst, for example an organicor inorganic acid such as p-toluenesulphonic acid, phosphoric acid andthe like, and at room temperature or at a temperature above roomtemperature for example between about 25° C. and about 150° C.

In accordance with embodiment (c) of the process, compounds of formula Ican be manufactured by dehydrogenating a compound of formula V or VI.Preferred reagents for this dehydrogenation include manganese dioxide,palladium-on-carbon and elemental oxygen, with atmospheric oxygen beingsufficient. However, potassium permanganate, for example, can also beused. Solvents in which this dehydrogenation can be carried out includechlorinated hydrocarbons such as methylene chloride and chloroform,aromatic hydrocarbons, dimethylformamide etc. The dehydrogenation iscarried out at room temperature or at a temperature above roomtemperature, conveniently between about 25° C. and about 200° C.

In accordance with embodiment (d) of the process, compounds of formula Ican be manufactured by converting the carboxamido group in a compound offormula VII into the nitrile group. This reaction is carried out in amanner known per se using a suitable dehydrating agent such asphosphorus pentoxide or the like in an inert organic solvent such asbenzene, toluene or the like at a temperature of from about 50° C. tothe boiling point of the reaction mixture. Preferably, commercialphosphorus pentoxide bound to an inert carrier is used as thedehydrating agent and the reaction is carried out in boiling toluene.

In accordance with embodiment (e) of the process, compounds of formula Ican be manufactured by appropriately substituting a compound of formulaIa at the secondary amino group in the 5-position. This substitution iscarried out according to methods known per se using an agent yieldingthe desired substituent R³¹ ; for example, a corresponding organicsulphonic acid alkyl ester (e.g. methyl p-toluenesulphonate), acorresponding dialkyl sulphate such as dimethyl sulphate or diethylsulphate, a corresponding alkyl halide such as methyl iodide, ethyliodide or ethyl bromide, or the like. The compound of general formula Iais conveniently used in the form of an alkali metal salt; this isconveniently achieved by allowing the reaction to proceed in thepresence of a strong base or by converting the compound of formula Iainto an alkali metal salt before the reaction with the alkylating agent.Suitable bases are alkali metal alkoxides such as sodium methoxide orpotassium tert.butoxide, alkali metal hydrides such as sodium hydride,alkali metal amides such as lithium amide or lithium diisopropylamide,and the like. The reaction is conveniently carried out in the presenceof an inert organic solvent. Suitable solvents for this purpose are, forexample, dimethylformamide, dimethyl sulphoxide, ethyl acetate, loweralkanols and the like; many other solvents and also solvent mixtures arealso suitable and their choice presents no difficulties to a personskilled in the art. The reaction temperature can be varied within fairlywide limits and generally lies between about room temperature and aboutthe boiling point of the reaction mixture.

In accordance with embodiment (f) of the process, compounds of formula Ican be manufactured by cleaving off the protecting group denoted by Z ina compound of formula VIII. In this embodiment there come intoconsideration only protecting groups which can be cleaved off under mildacid conditions, for example using dilute aqueous mineral acids such asdilute hydrochloric acid or dilute sulphuric acid, trifluoroacetic acidor the like, optionally with the addition of a CO-solvent such astetrahydrofuran, dioxan, acetic acid, N,N-dimethylformamide or the like.The cleavage is conveniently carried out at a temperature between aboutroom temperature and the boiling point of the mixture, the latter beingpreferred. An especially suitable protecting group is the2,4-dimethoxybenzyl group which is conveniently cleaved off usingtrifluoroacetic acid, preferably at the boiling point of the mixture.

In accordance with embodiment (g) of the process, compounds of formula Ican be manufactured by converting the oxime group in a compound offormula IX into the nitrile group according to methods known per se.This reaction is conveniently carried out using a suitable dehydratingagent; for example, a carboxylic acid anhydride (e.g. acetic anhydrideor propionic acid anhydride), a sulphonic acid halide (e.g.p-toluenesulphonyl chloride) in the presence of a base (e.g.triethylamine or the like), and the like, the reaction temperaturedepending on the method used. The reaction is preferably carried outusing acetic anhydride and at the boiling point of the reaction mixture.

In accordance with embodiment (h) of the process, compounds of formula Ican be manufactured by oxidising the hydroxyl group in a compound offormula X according to methods known per se. Suitable oxidising agentsare reagents which are generally used in such oxidations and which areknown to a person skilled in the art: for example, manganese dioxide,potassium permanganate, Jones' reagent and the like. Examples ofsuitable solvents are, depending on the oxidising agent used,halogenated hydrocarbons such as methylene chloride, chloroform and thelike, aromatic hydrocarbons such as benzene, toluene and the like,dimethylformamide, acetone, water etc. The oxidation is carried out at atemperature of from about 0° C. to the boiling point of the mixturedepending on the method used. In a preferred aspect, the oxidation iscarried out using manganese dioxide in a halogenated hydrocarbon such asmethylene chloride, chloroform or the like, conveniently at roomtemperature.

In accordance with embodiment (i) of the process, compounds of formula Ican be manufactured by trans-esterifying a compound of general formulaXI, i.e. by replacing the alkyl group denoted by R⁷ in a compound offormula XI with a group R⁴, whereby, of course, R⁷ and R⁴ representdifferent groups. Insofar as R⁷ in formula XI represents methyl, ethylor isopropyl, the compounds of formula XI fall within formula Ihereinbefore. R⁷ can, of course, also represent another lower alkylgroup.

This trans-esterification is carried out in a manner known per se byreacting a compound of formula XI with an alcohol corresponding to thedesired group denoted by R⁴ (i.e. methanol, ethanol, isopropanol orethyleneglycol) at room temperature or while warming to a temperature offrom about 25° C. to 150° C. Preferably, the trans-esterification iscarried out in the presence of a base, with potassium cyanide or similarweak bases being especially suitable in the present case. As the solventthere is preferably used the alcohol corresponding to the group denotedby R⁴ in the desired compound of formula I. However, thetrans-esterification can also be carried out in an inert organicsolvent, for example an aromatic hydrocarbon such as benzene or xylene,an ether such as dioxan, tetrahydrofuran or ethyleneglycol dimethylether, dimethylformamide, dimethyl sulphoxide or the like. In thistrans-esterification not only a low boiling alcohol can be replaced by ahigh boiling alcohol, but also a high boiling alcohol can be replaced bya low boiling alcohol; it is, for example, possible to convert ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateby means of methanol into methyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate.

The trans-esterification can, however, also be carried out in severalstages; for example, by hydrolysing a compound of formula XI to thecorresponding free carboxylic acid, preparing from this a reactivefunctional derivative (e.g. an acid chloride or the like) andsubsequently reacting this reactive carboxylic acid derivative with thealcohol corresponding to the significance of R⁴ in the desired compoundof formula I.

In accordance with embodiment (j) of the process, compounds of formulaIb can be converted into corresponding compounds of formula I in which Drepresents >C═S by reaction with a sulphurising agent, which can becarried out in a manner known per se. For example, the sulphurisingagent can be phosphorus pentasulphide, this being preferably used inexcess and the reaction being advantageously carried out in an inertorganic solvent such as dioxan, methylene chloride or the like in thepresence of triethylamine at a temperature of from about 50° C. to thereflux temperature of the reaction mixture. Other suitable sulphurisingagents are compounds such as2,4-bis(p-methoxyphenyl)-1,3,2,4-dithiaphosphetane-2,4-disulphide; suchsulphurising agents being used in approximately the calculated amountand the reaction being carried out in the presence of an inert solventsuch as toluene or xylene, conveniently at the reflux temperature of thereaction mixture or in hexamethyl-phosphoric acid triamide at atemperature between about 60° C. and 110° C.

In accordance with embodiment (k) of the process, compounds of formula Ican be converted into pharmaceutically acceptable acid addition salts.The manufacture of such pharmaceutically acceptable acid addition saltsis carried out according to generally usual methods. The salts providedby the present invention are salts formed with inorganic acids and withorganic acids; for example, hydrochlorides, hydrobromides, sulphates,methanesulphonates, p-toluenesulphonates, oxalates and the like.

The compounds of formula II hereinbefore used as starting materials inembodiment (a) of the process can be prepared starting from compounds ofthe general formula ##STR16##

wherein A, the dotted line, R²¹ and R³¹ have the significance givenearlier,

according to methods known per se; see, for example,

Belgian Patent Specifications Nos. 802 233, 833 249 and 865 653, U.S.Pat. No. 3,681,341 and J. Org. Chemistry 29, 231 (1964).

Various Examples hereinafter contain detailed information relating tothe preparation of compounds of formula II from compounds of formulaXII.

The compounds of formula XII, in turn, are known or can be readilyprepared according to methods known per se; for example, by reacting acorresponding carboxylic acid anhydride of the general formula ##STR17##wherein A and the dotted line have the significance given earlier,

with an amino acid of the general formula ##STR18## wherein R²¹ and R³¹have the significance given earlier.

Compounds of formula XII in which R²¹ represents hydrogen and R³¹represents lower alkyl can, however, also be prepared starting fromcompounds of the general formula ##STR19## wherein A, the dotted lineand R⁷ have the significance given earlier,

for example by treating such a compound with a reactive derivative of anα-haloacetic acid (e.g. α-chloroacetyl chloride) and reacting theintermediate obtained with a lower alkylamine (e.g. methylamine,ethylamine or the like). There are thus obtained compounds of thegeneral formula ##STR20## wherein A, the dotted line and R⁷ have thesignificance given earlier and R³² represents lower alkyl.

By cyclising compounds of formula XVI there are obtained compounds offormula XII in which R²¹ represents hydrogen and R³¹ represents loweralkyl. This cyclisation is carried out, for example, by heating acorresponding compound of formula XVI for a short time at a temperatureof from about 100° C. to about 300° C.

It is also possible to react a compound of formula XV with a reactivederivative of a carboxylic acid of the general formula ##STR21## whereinR²¹, R³¹ and Z have the significance given earlier,

for example a carboxylic acid chloride or the like. After removal of theprotecting group denoted by Z from a thus-obtained compound of thegeneral formula ##STR22## wherein A, the dotted line, R²¹, R³¹, R⁷ and Zhave the significance given earlier,

and cyclisation in analogy to the preparation of compounds of formulaXII from compounds of formula XVI, there is obtained a compound offormula XII.

In order to obtain a compound of the general formula ##STR23## wherein Aand the dotted line have the significance given earlier, the leavinggroup denoted by X in a compound of the general formula ##STR24##wherein A and the dotted line have the significance given earlier and Xrepresents a leaving group,

can be eliminated in a manner known per se. Examples of leaving groupsare sulphonic acid groups such as methanesulphonyloxy,p-toluenesulphonyloxy and the like, halogen atoms such as chlorine,bromine and iodine, and the like. The cleavage is carried out with abase such as sodium hydride in an inert organic solvent such asdimethylformamide.

Compounds of formula XIX can be prepared in analogy to the preparationof compounds of formula XII from compounds of formulae XIII and XIV orfrom compounds of formula XVIII.

Compounds of formula IV used as starting materials in embodiment (b) ofthe process and compounds of formulae V and VI used as startingmaterials in embodiment (c) of the process can be prepared according tomethods known per se (see Belgian Patent Specifications Nos. 833 248 and839 364) starting from compounds of formula II in accordance with thefollowing Reaction Scheme in which A, the dotted line, R²¹, R³¹, R⁴¹ andX have the significance given earlier: ##STR25##

Compounds of formula VII used as starting materials in embodiment (d) ofthe process can be readily prepared by treating a compound of thegeneral formula ##STR26## wherein A, the dotted line, D, R²¹, R³¹ and R⁷have the significance given earlier,

with ammonia according to methods known per se and familiar to a personskilled in the art. The amide formation can, however, also be carriedout in several stages; for example, by hydrolysing the compound offormula XIa to the corresponding free carboxylic acid, preparing fromthis a reactive functional derivative (e.g. an acid chloride, an acidimidazolide or the like) and subsequently reacting this reactivecarboxylic acid derivative with ammonia in a manner known per se.

Insofar as R⁷ in formula XIa represents methyl, ethyl or isopropyl, thecompounds of formula XIa fall within formula I hereinbefore. R⁷ can,however, also represent another lower alkyl group.

Compounds of formula VIII used as starting materials in embodiment (f)of the process can be prepared starting from compounds of the generalformula ##STR27## wherein A, the dotted line and Z have the significancegiven earlier,

in analogy to the methods described earlier in connection with themanufacture of compounds of formula I in which R² represents hydrogenand R³ represents lower alkyl, namely in analogy to embodiments (a),(b), (c), (d), (g), (h), (i) and (j) of the foregoing and to the methodsdescribed for the preparation of the corresponding starting materials.

The compounds of formula IX used as starting materials in embodiment (g)of the process are readily accessible from carboxylic acid esters offormula XI. For example, a carboxylic acid ester of formula XI can bereduced with a reduction agent such as lithium borohydride in an inertorganic solvent such as diethyl ether, tetrahydrofuran, dimethoxyethaneor the like to the corresponding primary alcohol which can subsequentlybe converted with a mild oxidising agent such as manganese dioxide orthe like in an inert organic solvent such as methylene chloride,chloroform or the like into the corresponding aldehyde of the generalformula ##STR28## wherein A, the dotted line, D, R² and R³ have thesignificance given earlier.

By treating an aldehyde of formula XXI with hydroxylamine there isobtained the corresponding oxime of formula IX. Conveniently,hydroxylamine hydrochloride is used as the reagent and the treatment iscarried out in an inert solvent such as, for example, water, methanol orethanol, mixtures of methanol or ethanol with water or the like, in thepresence of a base such as potassium carbonate, sodium carbonate,potassium hydroxide, sodium hydroxide, triethylamine or the like, or ina basic solvent such as pyridine, triethylamine or the like at atemperature of from about room temperature to the boiling point of themixture.

Compounds of formula X used as starting materials in embodiment (h) ofthe process are readily accessible from aldehydes of formula XXI. Analdehyde of formula XXI can be reacted with a metal-organic compoundyielding the group R⁷ according to methods which are generally known andfamiliar to a person skilled in the art. Metal-organic compounds whichcan be used are primarily Grignard compounds such as methyl-magnesiumiodide, ethyl-magnesium iodide, isopropyl-magnesium bromide,n-propyl-magnesium bromide, n-butyl-magnesium chloride and the like andlithium alkyl compounds such as methyl lithium, ethyl lithium, isopropyllithium, n-propyl lithium, n-butyl lithium and the like. Suitablesolvents are ethers such as diethyl ether, tetrahydrofuran, tert.butylmethyl ether, mixtures thereof and the like, and, when lithium alkylcompounds are used, also hydrocarbons such as pentane, hexane, heptane,benzene, toluene and the like. Conveniently, the reaction is carried outat the boiling point of the reaction mixture, but it can also be carriedout at a lower temperature (e.g. at room temperature).

Compounds of formula XI in which R⁷ represents a group other thanmethyl, ethyl or isopropyl, which are used as starting materials inembodiment (i) of the process, can be prepared in analogy to the methodsdescribed earlier in connection with the preparation of compounds offormula V in which R¹ represents a group of the formula --COOR⁴¹ whereinR⁴¹ has the significance given earlier; namely in analogy to embodiments(a), (b), (c), (e), (f), and (j) of the process and to the methodsdescribed for the preparation of the corresponding starting materials.Compounds of formula XI in which R⁷ represents other than methyl, ethylor isopropyl are novel and also form part of the present invention.

The compounds of formulae II, IV, V, VI, VII, VIII, IX and X are noveland also form part of the present invention.

As mentioned earlier, the compounds of formula I are novel and possessextremely valuable pharmacodynamic properties. They have only a lowtoxicity, and it has been shown that they have a pronounced affinity tothe central benzodiazepine receptors and are capable of antagonising thecentral-depressant, muscle relaxant, ataxic, blood pressure-lowering andrespiratory-depressant properties of 1,4-benzodiazepines which havetranquillising activity.

The affinity of compounds of formula I to the central benzodiazepinereceptors was determined according to the method described in LifeScience 20, 2101-2110 (1977) and Science 198, 849-851 (1977). Accordingto this method, the inhibition of the binding of tritiated diazepam atthe specific benzodiazepine receptors in the cerebral cortex by testsubstances is ascertained. The IC₅₀ ("50% inhibiting concentration") isthat concentration of the test substance which brings about a 50 percentinhibition of the specific binding of the tritiated diazepam at thespecific benzodiazepine receptors in the cerebral cortex.

One of the typical properties of 1,4-benzodiazepines, which havetranquillising activity, in experimental animals is their pronouncedanticonvulsive activity which can be demonstrated, for example, in theknown and generally recognised pentetrazole test. This property was usedas a basis for the test described hereinafter which permits thedetermination of compounds which are capable of antagonising the centralproperties of 1,4-benzodiazepines which have tranquillising activity.

In this test, 5 mg/kg (i.p.) of diazepam (a supramaximal dosage, whichin the pentetrazole test on more than 900 mice protected allexperimental animals from spasmodic seizures) were administered to mice1 hour before the pentetrazole (120 mg/kg, i.p.) and the compound to betested was administered 15 minutes before the pentetrazole. Theantagonistic activity of the compounds tested, i.e. their ability tocounteract the activity of diazepam in the pentetrazole test, isdetermined by counting the mice which suffer spasmodic seizures in thistest.

In the following Table there are compiled the results which have beenobtained with representative compounds of formula I. The ED₅₀ value isgiven for each compound listed in the Table. The ED₅₀ is the amount ofthe test compound in mg/kg (p.o.) which counteracts in 50% of theanimals the diazepam effect in the foregoing test. Moreover, the Tablecontains the IC₅₀ value (defined hereinbefore) for all test compoundslisted therein as well as details concerning the acute toxicity ofcertain compounds (LD₅₀ in mg/kg following single oral administration tomice).

                                      TABLE                                       __________________________________________________________________________    Imidazo[1,5-a][1,4]benzodiazepine derivatives, i.e. compounds of formula      I in which                                                                    A represents group (a)                                                                           Config-       IC.sub.50 in                                                                      ED.sub.50 in                                                                        LD.sub.50 in                       R.sup.1  R.sup.2                                                                           R.sup.3                                                                             uration                                                                           R.sup.5                                                                         R.sup.6                                                                           D   μM/l                                                                           mg/kg p.o.                                                                          mg/kg p.o.                         __________________________________________________________________________    --COOC.sub.2 H.sub.5                                                                   H   --CH.sub.3                                                                          --  F H   C═O                                                                           2.5 5.8   >5000                              --COOC.sub.2 H.sub.5                                                                   --(CH.sub.2).sub.3 --                                                                   S   H H   C═O                                                                           6.4 9.3   1250-2500                          --COOC.sub.2 H.sub.5                                                                   H   --CH.sub.3                                                                          --  H H   C═O                                                                           3.0 10.9  >5000                              --COOC.sub.2 H.sub.5                                                                   H   --CH.sub.3                                                                          --  H H   C═S                                                                           6.0 8.9                                      --COOCH.sub.3                                                                          H   --CH.sub.3                                                                          --  H H   C═O                                                                           9.0 13.5                                     --COOCH(CH.sub.3).sub.2                                                                H   --CH.sub.3                                                                          --  H H   C═O                                                                           12.0                                                                              7.0                                      --COOCH.sub.3                                                                          H   --CH.sub.3                                                                          --  F H   C═O                                                                           6.0 4.9                                      --COOCH(CH.sub.3).sub.2                                                                H   --CH.sub.3                                                                          --  F H   C═O                                                                           3.9 6.6   >5000                              --COOC.sub.2 H.sub.5                                                                   H   --CH.sub.3                                                                          --  H F   C═O                                                                           2.0 2.1   >5000                              --COOC.sub.2 H.sub.5                                                                   H   --CH.sub.3                                                                          --  H Cl  C═O                                                                           3.0 0.48                                     --COOC.sub.2 H.sub.5                                                                   H   --CH.sub.3                                                                          --  H --CH.sub.3                                                                        C═O                                                                           5.0 7.1                                      --COOCH.sub.3                                                                          --(CH.sub.2).sub.3 --                                                                   S   H H   C═O                                                                           32.0                                                                              3.5   2000-4000                          --COOCH(CH.sub.3).sub.2                                                                --(CH.sub.2).sub.3 --                                                                   S   H H   C═O                                                                           3.0 18.6                                     --COOC.sub.2 H.sub.5                                                                   --(CH.sub.2).sub.3 --                                                                   S   F H   C═O                                                                           6.0 8.9                                      --COOC.sub.2 H.sub.5                                                                   --(CH.sub.2).sub.3 --                                                                   S   H Cl  C═O                                                                           1.7 1.0    750-1500                          --COOC.sub.2 H.sub.5                                                                   --(CH.sub.2).sub.3 --                                                                   S   H --CH.sub.3                                                                        C═O                                                                           5.0 6.5                                      --COOC.sub.2 H.sub.5                                                                   H   --CH.sub.3                                                                          --  F H   C═S                                                                           2.5 6.3                                      --CN     H   --CH.sub.3                                                                          --  H H   C═O                                                                           100.0                                                                             2.6    1250                              --CN     H   --CH.sub.3                                                                          --  F H   C═O                                                                           93.0                                                                              4.2                                      --CN     --(CH.sub.2).sub.3 --                                                                   S   H H   C═O                                                                           31.0                                                                              12.1                                     --COOC.sub.2 H.sub.5                                                                   --CH═CH--CH.sub.2 --                                                                R/S H H   C═O                                                                           2.3 3.9                                      --COOC.sub.2 H.sub.5                                                                   --CH═CH--CH.sub.2 --                                                                R/S H F   C═O                                                                           2.1 1.8    500-1000                          __________________________________________________________________________

Imidazo[1,4-a]thieno[2,3-f][1,4]diazepine derivatives, i.e. compounds offormula I wherein A signifies the group (b):

    ______________________________________                                                                     Config-                                                                             IC.sub.50 in                                                                        ED.sub.50 in                         R.sup.1  R.sup.2                                                                             R.sup.3 D     uration                                                                             μM/l                                                                             mg/kg p.o.                           ______________________________________                                        --COOCH.sub.3                                                                          --(CH.sub.2).sub.3 --                                                                   C═O S     2.1   0.22                                   --COOC.sub.2 H.sub.5                                                                   --(CH.sub.2).sub.3 --                                                                   C═O S     0.9   1.3                                    --COOC.sub.2 H.sub.5                                                                   H     --CH.sub.3                                                                            C═O                                                                             --    1.1   12.6                                 --COOCH.sub.3                                                                          H     --CH.sub.3                                                                            C═O                                                                             --    1.2   0.83                                 ______________________________________                                    

From the tests described hereinafter it is evident that one compound offormula I, ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylatereferred to as "test substance" hereinafter), antagonises the centralactivities of the known 1,4-benzodiazepine derivative diazepam:

Male albino rats (body weight about 165 g) are used for this test.Diazepam is administered to these animals in a dosage of 5 mg/kg i.v.,so that they fall asleep immediately, no longer show rousing reflex,sleep for at least 60 minutes in the lateral position and slowly wake upafter about 1.5 hours; if diazepam is administered to the animals in adosage of 10 mg/kg i.p., they fall asleep within a few minutes, sleepfor ca 2-3 hours and then slowly wake up. If the test substance in adosage of 5 mg/kg i.v. is given to the animals 5 or 15 minutes after theadministration of 5 mg/kg i.v. of diazepam or 30 minutes after theadministration of 10 mg/kg i.p. of diazepam, then the animals stand upimmediately and move around, this waking phase lasting for 30 minutes to1 hour.

If the test substance is given to the animals in a dosage of 20 mg/kgi.p., then the animals remain awake and show a normal behaviour; ifdiazepam is then administered to them after 30 minutes in a dosage of 5mg/kg i.v., then they show in the first 2 minutes after the injectionslight sedation and ataxia, but these symptoms rapidly disappear and thewaking phase lasts for at least 30 minutes.

From the tests described hereinafter it is evident that one compound offormula I, ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]-pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate(referred to as "test substance" hereinafter), antagonises the centralactivities of the known 1,4-benzodiazepine derivative flunitrazepam:

Four tests were carried out on conscious, curarised, artificiallyrespirated rats. The bipolar-derived EEG of the dorsal hippocampusserved as the measured variable. 10 minutes after the beginning of thederivation flunitrazepam was administered intravenously in a dosage of0.1 mg/kg. The test substance was likewise administered intravenously ina dosage of 1 mg/kg to one animal 10 minutes and to three animals 30minutes after the administration of flunitrazepam. The EEGs obtainedwere analysed continuously in the frequency range according to the rulesof the Fourier transformation, whereby each of the computed spectrarelated to 1 minute.

The normal EEG from the hippocampus of conscious, curarised rats ischaracterised by a stable theta rhythm of 3.75-4.25 Hertz which remainsunchanged at least 3 hours after the beginning of the artificialrespiration. Flunitrazepam, in the given dosage, completely suppressesthis theta rhythm for about 15 minutes. Thereafter, there appears arhythm which is slowed down to 2.75-3.25 Hertz, which increasescontinuously and again attains the normal frequency of 4 Hertz 1 to 1.5hours after the injection.

The test substance leads, in the specified dosage and at the specifiedtimes after flunitrazepam, to an immediate, long-lasting normalisationof the described theta rhythm at 4 Hertz. When the test substance wasadministered 10 minutes after flunitrazepam, then it immediatly broughtabout the rhythm suppressed by flunitrazepam, whereby this showed thenormal frequency from the outset. When the test substance wasadministered 30 minutes after flunitrazepam, then it accelerated thealready, but slowly, re-appearing rhythm immediately to its normalfrequency of 4 Hertz.

As mentioned earlier, compounds of formula I antagonise thecentral-depressant, muscle relaxant, ataxic, blood pressure-lowering andrespiratory-depressant properties of 1,4-benzodiazepines which havetranquillising activity. The latter are in widespread use in therapy andare often administered in high dosages, so that the above-mentionedactivities can also appear strongly as side-effects. The compounds offormula I can be used as antidotes in the case of intoxications in whichexcessive intake of 1,4-benzodiazepines which have tranquillisingactivity participates. They are also suitable for shortening anaesthesiain surgery and in obstetrics induced by 1,4-benzodiazepines which havetranquillising activity. In the case of neonatals, a possiblerespiratory depression, which is caused by the administration of1,4-benzodiazepines which have tranquillising activity to the mother,can be counteracted. The compounds of formula I can also be used tosuppress, in the case of 1,4-benzodiazepines which are used in otherfields of indication, the activities on the central nervous system whichare undesirable in such fields. Examples of such 1,4-benzodiazepineswhich can be used in other fields of indication areschistosomicidally-active 1,4-benzodiazepine derivatives of the generalformulae ##STR29## wherein R⁸ is hydrogen or lower alkyl and R⁹ ishalogen, and ##STR30## wherein R is hydrogen or lower alkyl and R¹⁰ isselected from the group consisting of hydrogen, halogen ortrifluoromethyl,

which are described in British Patent Specification Nos. 1,444,529 and1,474,305. An example of such a schistosomicidally-active1,4-benzodiazepine derivative is(+)-5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2-one.

The following tests show that representative compounds of formula I,which suppress the strong, but undesirable, central activities of thehighly active schistosomicide(+)-5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2-oneon the central nervous system, are in no way detrimental to itsschistosomicidal activity.

Mice and golden hamsters are infected subcutaneously with 60 cercaria ofSchistosoma mansoni. Ca 42 days after the infection, they are treatedorally with a single dosage of the compound to be tested. 5 animals areused per test preparation and dosage. 10 untreated animals are used ascontrols. The animals are killed and dissected 2 weeks (hamster) or 3weeks (mice) after the treatment. Worm pairs in mesenteric veins, portalvein and liver are dissected-out, counted and the condition of the worms(living or dead) is registered. A schistosomicidal activity of a testpreparation manifests itself in the appearance of dead worms in thevessels of the liver. Dead worms are never found in untreated controlanimals. The test is evaluated by calculating the percentage of deadworm pairs in the vessels of the liver in infected, treated animals.

In order to test the in vitro activity of preparations, worm pairs ofSchistosoma mansoni are isolated from mice and incubated at 37° C. in anutrient medium. Test preparations are added in the form of a solutionor as a suspension. The motility of the worms is observed under themicroscope and registered during the test duration of 120 hours. Aschistosomicidal activity of a test preparation manifests itself in themore or less rapid loss of motility of the worms. Control worms in thenutrient medium without the addition of test preparation maintain theirnormal motility during the entire test duration of 120 hours.

The following representative compounds of formula I were tested in testsdescribed earlier for possible detrimental effects on theschistosomicidal activity of(+)-5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2-one(compound S).

    ______________________________________                                        Ethyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-                                    4H-imidazo[1,5-a][1,4]benzodiazepine-3-                                       carboxylate             (compound A);                                         ethyl (S)-11,12,13,13a-tetrahydro-3-oxo-                                      9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]-                                         benzodiazepine-1-carboxylate                                                                          (compound B);                                         ethyl 5,6-dihydro-5-methyl-6-oxo-4H-                                          imidazo[1,5-a][1,4]benzodiazepine-                                            3-carboxylate           (compound C);                                         and                                                                           ethyl 5,6-dihydro-5-methyl-6-thioxo-                                          4H-imidazo[1,5-a][1,4]benzodiazepine-                                         3-carboxylate           (compound D).                                         ______________________________________                                    

As is evident from the following compilations relating to the results ontest animals and in the in vitro test, the schistosomicidal activity of(+)-5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2-one(compound S) was not influenced detrimentally by any of the compounds ofgeneral formula I which were tested.

    ______________________________________                                        Test results in mice and hamsters                                                                               Schistoso-                                                           Dosage   micidal                                     Host   Dosage in mg/kg p.o.                                                                            ratio    activity in %                               ______________________________________                                               Compound S Compound A                                                  ______________________________________                                        Mouse  75         --         --     99                                               --         750        --     0                                                75         225        1:3    98                                               75         750         1:10  93                                               --         --         --     0                                         Hamster                                                                              75         --         --     100                                              75         225        1:3    100                                              --         --         --     0                                         ______________________________________                                               Compound S Compound B                                                  ______________________________________                                        Mouse  75         300        1:4    91                                        Hamster                                                                              75         300        1:4    91                                        ______________________________________                                               Compound S Compound C                                                  ______________________________________                                        Mouse  75         150        1:2    99                                        Hamster                                                                              75         150        1:2    100                                       ______________________________________                                               Compound S Compound D                                                  ______________________________________                                        Mouse  75         150        1:2    93                                               75         750         1:10  98                                        Hamster                                                                              75         150        1:2    100                                       ______________________________________                                    

    ______________________________________                                        Results of in vitro experiments.                                              Preparation concentration                                                                       Concentration                                               in μg/ml       ratio        Activity*                                      ______________________________________                                        Compound S                                                                              Compound A                                                          ______________________________________                                        25        --          --           a                                          --         75         --           b                                          --        750         --           b                                          25         75         1:3          a                                          25        750          1:10        a                                          --        --          --           b                                          ______________________________________                                        Compound S                                                                              Compound B                                                          ______________________________________                                        --        100         --           b                                          25        100         1:4          a                                          ______________________________________                                        Compound S                                                                              Compound C                                                          ______________________________________                                        --        100         --           b                                          25         50         1:2          a                                          ______________________________________                                        Compound S                                                                              Compound D                                                          ______________________________________                                        --         50         --           b                                          --        250         --           b                                          25         50         1:2          a                                          25        250          1:10        a                                          ______________________________________                                         Activity:                                                                     a = worm pairs motionless within 15 minutes;                                  b = worm pairs show normal motility during the test duration of 120 hours                                                                              

The compounds of formula I and their pharmaceutically acceptable acidaddition salts can be used as medicaments, for example in the form ofpharmaceutical preparations. The pharmaceutical preparations can beadministered orally, for example in the form of tablets, coated tablets,dragees, hard and soft gelatin capsules, solutions, emulsions orsuspensions. The administration can, however, also be carried outrectally (e.g. in the form of suppositories) or parenterally (e.g. inthe form of injection solutions).

For the manufacture of tablets, coated tablets, dragees and hard gelatincapsules, the compounds of formula I and their pharmaceuticallyacceptable acid addition salts can be processed with pharmaceuticallyinert, inorganic or organic carriers. Examples of such carriers whichcan be used for tablets, dragees and hard gelatin capsules are lactose,maize starch or derivatives thereof, talc, stearic acid or its saltsetc.

Suitable carriers for soft gelatin capsules are, for example, vegetableoils, waxes, fats, semi-solid and liquid polyols etc.

Suitable carriers for the manufacture of solutions and syrups are, forexample, water, polyols, saccharose, invert sugar, glucose and the like.

Suitable carriers for injection solutions are, for example, water,alcohols, polyols, glycerine, vegetable oils etc.

Suitable carriers for suppositories are, for example, natural orhardened oils, waxes, fats, semi-liquid or liquid polyols and the like.

The pharmaceutical preparations can also contain preserving agents,solubilising agents, stabilising agents, wetting agents, emulsifiers,sweetening agents, colouring agents, flavouring agents, salts forvarying the osmotic pressure, buffers, coating agents or antioxidants.They can also contain still other therapeutically valuable substances.

As mentioned earlier, compounds of formula I and pharmaceuticallyacceptable acid addition salts thereof can be used in accordance withthe invention in the control or prevention of illnesses, especially inthe antagonisation of the central-depressant, muscle relaxant, ataxic,blood pressure-lowering and respiratory-depressant properties of1,4-benzodiazepines which have tranquillising activity. In particular,compounds of formula I can be used in the control of schistosomiasis incombination with the schistosomicidally-active 1,4-benzodiazepinederivatives of formula XXII and/or XXIII mentioned earlier. In thiscase, ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateis preferably used as the compound of formula I and(+)-5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2-oneis preferably used as the schistosomicidally-active 1,4-benzodiazepinederivative. The compounds of formula I or their pharmaceuticallyacceptable acid addition salts can be administered before,simultaneously with or after the administration or intake of1,4-benzodiazepines which have tranquillising activity. If the compoundof formula I or a pharmaceutically acceptable acid addition salt thereofis administered simultaneously with the 1,4-benzodiazepine which hastranquillising activity, then this administration can be as an ad-hoccombination or in the form of a pharmaceutical combination whichcontains a compound of formula I or a pharmaceutically acceptable acidaddition salt thereof and a 1,4-benzodiazepine derivative which hastranquillising activity; said pharmaceutical combinations also form partof the present invention. The dosage of compounds of formula I and theirpharmaceutically acceptable acid addition salts can vary within widelimits and is, of course, fitted to the individual requirements in eachparticular case. In general, a daily dosage of about 2 mg to about 500mg should be appropriate.

As mentioned earlier, medicaments containing a compound of formula I ora pharmaceutically acceptable acid addition salt thereof also form partof the present invention, as does a process for the manufacture of suchmedicaments which comprises bringing one or more compounds of formula Ior pharmaceutically acceptable acid addition salts thereof and, ifdesired, one or more other therapeutically valuable substances into agalenical administration form; in this connection reference is againmade to the pharmaceutical combinations mentioned earlier which alsoform part of the present invention. In particular, pharmaceuticalcombinations containing a compound of formula I and a benzodiazepinederivative of formula XXII and/or XXIII, preferably combinationscontaining ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateand(+)-5-(o-chlorophenyl)-1,3-dihydro-3-methyl-7-nitro-2H-1,4-benzodiazepin-2-one,form part of the present invention. Such combinations are suitable forthe control of schistosomiasis.

The following Examples illustrate the present invention:

EXAMPLE 1

(a) 24 g (132.5 mmol) of 5-fluoroisatoic acid anhydride are dissolved in140 ml of dimethyl sulphoxide and treated with 11.8 g (132.5 mmol) ofsarcosine. The solution is stirred at 100° C. until the gas evolutionceases (duration: ca 1.5 hours) and subsequently poured into ca 1.2liters of water. After stirring for 10 minutes, a solid crystallisesout. The crystals are filtered off under suction, washed with 1 liter ofwater and dried. There is obtained7-fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione ofmelting point 262°-263° C.

(b) A solution of 6.5 g (32 mmol) of7-fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione in 30ml of dry dimethylformamide is treated with 4,3 g (38 mmol) of potassiumtert.butylate under an argon atmosphere. The temperature thereby risesto 35° C. After 10 minutes, the mixture is cooled to -30° C. and 5.8 g(34 mmol) of diethylchlorophosphate are added dropwise thereto at -30°C. to -20° C. The solution is subsequently stirred at -20° C. for 10minutes.

Separately, 4 g (35 mmol) of potassium tert.butylate are dissolved in 10ml of dimethylformamide and treated at ca -40° C. with 4 g (35 mmol) ofethyl isocyanoacetate. This solution is added dropwise at -10° C. to-20° C. to the mixture obtained according to the preceding paragraph.The resulting mixture is then stirred without cooling for 1 hour, 3.2 mlof glacial acetic acid are added thereto, the mixture is poured into ca400 ml of water and extracted three times with 150 ml of ethyl acetateeach time. The combined organic extracts are washed five times with 200ml of water each time, dried over magnesium sulphate and evaporated.From the oily residue there is obtained, by column chromatography onsilica gel and subsequent recrystallisation from ethyl acetate andether, ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 199°-200° C.

EXAMPLE 2

(a) A mixture of 20.82 g (100 mmol) of7-fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione and200 ml of chloroform is heated to boiling under reflux for 2.5 hourswith 121.18 g (1 mol) of dimethylaniline and 23 g (150 mmol) ofphosphorus oxychloride. The solution is poured into a mixture of 71 g ofsodium bicarbonate and 500 ml of water and stirred for 0.5 hour. Themixture is extracted twice with chloroform, the chloroform phases arewashed with water and dried over magnesium sulphate. After removal ofthe solvent, there are obtained 162.2 g of a yellow solution of thecorresponding iminochloride in dimethylaniline.

Separately, 8.41 g (75 mmol) of potassium tert.butylate are dissolved in30 ml of dimethylformamide and treated at ca 40° C. with 8.48 g (75mmol) of ethyl isocyanoacetate. To this solution are added dropwise at-5° C. to 0° C. 81.1 g of the foregoing iminochloride solution indimethylaniline and the mixture obtained is stirred without cooling for10 minutes before it is neutralised with 7.5 ml of acetic acid. Themixture is poured into water and extracted three times with chloroform.The chloroform extracts are washed five times with water, dried overmagnesium sulphate and evaporated. By recrystallisation of the crudeproduct from alcohol there is obtained ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 200°-203° C.

(b) The remaining 81.1 g of the iminochloride solution indimethylaniline, obtained according to paragraph (a), are added dropwiseat 0° C. to a pre-cooled solution of 7.59 g (75 mmol) of triethylamineand 8.48 g (75 mmol) of ethyl isocyanoacetate in 30 ml ofdimethylformamide. After stirring at room temperature overnight, thelight brown solution is diluted with water and extracted three timeswith chloroform. The combined chloroform extracts are washed five timeswith water, dried over magnesium sulphate and evaporated. The residue isrecrystallised from alcohol and gives ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 201°-203° C.

EXAMPLE 3

A mixture of 3.5 g (11.5 mmol) of ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,0.15 g of potassium cyanide and 40 ml of methanol is stirred at theboiling point for 2.5 hours. The solvent is distilled off on a rotaryevaporator and the residue is taken up in chloroform. After filtrationfrom insoluble material, the filtrate is concentrated. Afterrecrystallisation of the residue from ethyl acetate, there is obtainedmethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 195°-196.5° C.

EXAMPLE 4

100 ml of 2-propanol are treated with 100 mg of sodium hydride. 5 g ofethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateare added thereto and the mixture is heated to boiling under reflux for1 hour. Subsequently, the mixture is left to cool to room temperature,the separated crystals are filtered off and washed with 2-propanol andwater, there being obtained isopropyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 243°-244° C.

EXAMPLE 5

A mixture of 6.08 g (20 mmol) of ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,100 mg of potassium cyanide and 60 ml of ethyleneglycol is stirred at130° C. for 6 hours and subsequently evaporated. After taking up theresidue in chloroform, the solution is washed with water, dried overmagnesium sulphate and evaporated. After recrystallisation of the crudeproduct from ethyl acetate, there is obtained 2-hydroxyethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 202°-204° C.

EXAMPLE 6

10.7 g (35.3 mmol) of ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateand 7.13 g (17.6 mmol) of2,4-bis(p-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulphide in100 ml of toluene are heated to boiling under reflux for 22 hours. Themixture is subsequently concentrated in vacuo until crystallisationbegins and is then left to stand in an ice-bath for 1 hour. Thecrystallised-out material is filtered off under suction and washed witha small amount of toluene. The mixture is separated on silica gel withethyl acetate/chloroform (1:9). After recrystallisation from ethylacetate, there is obtained pure ethyl8-fluoro-5,6-dihydro-5-methyl-6-thioxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 157°-159° C.

EXAMPLE 7

(a) 15.0 g (49.5 mmol) of ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateare dissolved under argon in 450 ml of boiling absolute tetrahydrofuran(filtered over Alox) and added dropwise at 50° C. to a solution of 1.1 g(49.5 mmol) of lithium borohydride in 50 ml of absolute tetrahydrofuran.The mixture is stirred at 40° C. for 4 hours and at the boiling pointfor 2.5 hours. Subsequently, the mixture is decomposed at 40° C. with 20ml of water and 20 ml of concentrated hydrochloric acid/water (1:1) andstirred at room temperature overnight. After removal of thetetrahydrofuran in vacuo, the residue is treated with 14 ml ofconcentrated ammonia. The mixture is left to crystallise in the cold andseparated material is filtered off under suction and washed with water.After recrystallisation from ethanol, there is obtained8-fluoro-4,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one of melting point 221°-223° C.

(b) A suspension of 4.93 g (18.9 mmol) of8-fluoro-4,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[1,5-a][1,4]-benzodiazepin-6-onein 220 ml of methylene chloride is treated with 30 g of manganesedioxide and the mixture is stirred at room temperature of 1.5 hours.After filtration over Dicalit, the filtrate is evaporated in vacuo andthe residue is recrystallised from ethanol. There is thus obtained8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehydeof melting point 224°-226° C.

(c) A solution of 4.14 g (14.5 mmol) of sodium carbonate decahydrate in20 ml of water is added dropwise to a mixture of 3.0 g (11.6 mmol) of8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde,0.99 g (14.5 mmol) of hydroxylamine hydrochloride and 60 ml of water,the mixture is stirred at 70° C. for 1 hour, cooled in an ice-bath andthe separated material is filtered off under suction and washed withwater. The still moist substance is recrystallised from ethanol andyields8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde-3-oximeof melting point 247°-250° C.

(d) 1.65 g (6 mmol) of8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde-3-oximeare heated to boiling under reflux for 4.5 hours in 15 ml of acetic acidanhydride and the mixture is evaporated. The residue is taken up in 100ml of chloroform and the solution is washed once with saturated sodiumhydrogen carbonate solution and once with water. The chloroform solutionis dried over magnesium sulphate and concentrated. After columnchromatography and recrystallisation from ethyl acetate, there isobtained8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carbonitrileof melting point 236°-237° C.

EXAMPLE 8

(a) A solution of 23.7 g of 5-fluoroisatoic acid anhydride and 29.5 g ofN-(2,4-dimethoxybenzyl)-glycine in 130 ml of dimethyl sulphoxide isheated at 100° C. for 1.5 hours. The mixture is cooled to roomtemperature and poured into 400 ml of water. The separated product isfiltered off under suction and washed with water. There is thus obtained4-(2,4-dimethoxybenzyl)-7-fluoro-3,4-dihydro-2H-1,4-benzodiazepine-2,5(1H)-dioneof melting point 190°-192° C.

(b) 27 g (78 mmol) of4-(2,4-dimethoxybenzyl)-7-fluoro-3,4-dihydro-2H-1,4-benzodiazepine-2,5(1H)-dioneare placed in 75 ml of dry dimethylformamide and treated with 9.6 g (86mmol) of potassium tert.butylate. The temperature rises to 40° C. andthe solution is stirred at room temperature for 10 minutes before it iscooled to -30° C. At this temperature there are added dropwise 14.2 g(82 mmol) of diethylchlorophosphate and the mixture is stirred at -20°C. for 10 minutes.

Separately, 9.7 g (86 mmol) of potassium tert.butylate are dissolved in20 ml of dry dimethylformamide, the solution is cooled to -50° C. andtreated with 9.8 g (86 mmol) of ethyl isocyanoacetate. This solution isimmediately added dropwise at -20° C. to -10° C. to the mixture obtainedaccording to the preceding paragraph. The resulting mixture is stirredwithout cooling for 1 hour, 7.8 ml of glacial acetic acid are addedthereto, the mixture obtained is poured into 1 liter of water andextracted three times with 200 ml of ethyl acetate each time. Thecombined organic extracts are washed five times with 250 ml of watereach time, dried over magnesium sulphate and evaporated. Afterrecrystallisation from 150 ml of ethyl acetate, there is obtained ethyl5-(2,4-dimethoxybenzyl)-8-fluoro-5,6-dihydro-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 159°-160° C.

(c) 13.0 g (29.6 mmol) of ethyl5-(2,4-dimethoxybenzyl)-8-fluoro-5,6-dihydro-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateare heated to boiling under reflux for 4 hours in 45 ml oftrifluoroacetic acid. After evaporation of the dark red suspension invacuo, the residue is treated with water and made alkaline with ca 100ml of 15 percent potassium carbonate solution. The separated material isfiltered off under suction and washed with water. Afterrecrystallisation from ca 500 ml of ethanol, there is obtained ethyl8-fluoro-5,6-dihydro-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 298° C.

EXAMPLE 9

0.1 g (2 mmol) of sodium hydride (55 percent oil dispersion) aresuspended in 10 ml of dry dimethylformamide and treated with 0.5 g (1.7mmol) of ethyl8-fluoro-5,6-dihydro-6-oxo-4H-imidazo[1,5,-a][1,4]benzodiazepine-3-carboxylate.After completion of the gas evolution, 0.13 ml (2 mmol) of methyl iodideis added and the mixture is stirred at room temperature for 2 hours. Themixture is poured into ca 60 ml of water and extracted three times with30 ml of chloroform each time. The combined chloroform extracts arewashed with ca 30 ml of water, dried over magnesium sulphate andevaporated. After recrystallisation from ethyl acetate, there isobtained ethyl8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 196°-197° C.

EXAMPLE 10

(a) A mixture of 34.5 g (0.22 mol) of 6-fluoro-2-nitrotoluene, 30.7 g(0.22 mol) of potassium carbonate, 105.4 g (0.66 mol) of potassiumpermanganate and 3.3 liters of water is heated at 100° C. until thepermanganate is decolorised (ca 2.5 hours). After cooling and removal ofthe unreacted 6-fluoro-2-nitrotoluene by extraction with ethyl acetate,the aqueous phase is adjusted to pH 1 with hydrochloric acid andextracted three times with ethyl acetate. The combined organic extractsare dried over magnesium sulphate and concentrated, there being obtained6-fluoro-2-nitrobenzoic acid. After recrystallisation from ethylacetate/n-hexane, the product melts at 146°-148° C.

(b) 2.7 g of 10 percent palladium/carbon are added to a solution of 20.0g (0.108 mol) of 6-fluoro-nitrobenzoic acid in a mixture of 200 ml ofmethanol and 27 ml of concentrated hydrochloric acid and the resultingmixture is hydrogenated at 35°-40° C. under a slight over-pressure.After filtration of the catalyst and concentration of the filtrate, thecrude product is recrystallised from methanol/ether. There is obtained6-fluoroanthranilic acid hydrochloride of melting point 176°-178° C.(decomposition).

(c) Phosgene is conducted at 35°-40° C. for 3 hours into a solution of23 g (0.148 mol) of 6-fluoroanthranilic acid hydrochloride in a mixtureof 300 ml of tetrahydrofuran and 150 ml of 4 N hydrochloric acid. Afterremoval of the phosgene, the mixture is diluted with 500 ml of water andthe precipitate is filtered off. There is obtained crude 6-fluoroisatoicacid anhydride of melting point 265°-267° C. (decomposition).

(d) 7.2 g (0.04 mol) of 6-fluoroisatoic acid anhydride and 3.9 g (0.044mol) of sarcosine are added to 10 ml of dimethyl sulphoxide and themixture is heated at 100° C. for 30 minutes. After cooling and dilutingwith 15 ml of water, the separated substance is filtered off. Afterdrying, there is obtained6-fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione ofmelting point 214°-217° C. (decomposition).

(e) 3.18 g (15.2 mmol) of6-fluoro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione in 20ml of dimethylformamide are treated under an argon atmosphere with 0.59g (15.2 mmol) of sodium hydride (60 percent oil dispersion) and stirredfor 1 hour. The solution obtained is cooled to -30° C. and treateddropwise at this temperature with 2.63 g (15.2 mmol) ofdiethylchlorophosphate. The mixture is subsequently stirred at -20° C.for 10 minutes.

Separately, 1.79 g (16 mmol) of potassium tert.butylate are dissolved in3 ml of dimethylformamide and treated at -40° C. to -50° C. with 1.18 g(16 mmol) of ethyl isocyanoacetate. The resulting orange colouredsolution is added dropwise at -15° C. to the mixture obtained accordingto the preceding paragraph. The resulting mixture is stirred withoutcooling for 10 minutes, neutralised with 1.50 ml of acetic acid and thedark brown solution is poured into water. After three-fold extractionwith 60 ml of chloroform each time, the combined chloroform phases arewashed five times with 150 ml of water each time and evaporated. Afterrecrystallisation of the crude product from ethyl acetate, there isobtained ethyl7-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 196°-198.5° C.

EXAMPLE 11

(a) 7.2 g (0.04 mol) of 6-fluoroisatoic acid anhydride and 5 g (0.044)mol of (S)-3,4-dehydroproline are added to 10 ml of dimethyl sulphoxideand heated at 100° C. for 45 minutes. After cooling and diluting with 15ml of water, the separated crystals are filtered off. After drying,there is obtained(S)-6-fluoro-3,11a-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dioneof melting point 238°-240° C.

(b) A mixture of 4.64 g (20 mmol) of(S)-6-fluoro-3,11a-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dioneand 25 ml of dimethylformamide is treated under argon with 0.80 g (22mmol) of sodium hydride (60 percent oil dispersion) and stirred at atemperature between 0° C. and 10° C. for 1 hour. The solution obtainedis cooled to -30° C. and treated with 3.79 g (22 mmol) ofdiethylchlorophosphate. The resulting mixture is stirred at -20° C. for10 minutes.

Separately, a solution of 2.24 g (22 mmol) of potassium tert.butylate in5 ml of dimethylformamide is treated in an acetone/dry-ice bath with2.26 g (20 mmol) of ethyl isocyanoacetate. The solution obtained isadded dropwise at -20° C. to -10° C. to the mixture obtained accordingto the preceding paragraph. The resulting mixture is stirred withoutcooling for 10 minutes, neutralised with 2 ml of acetic acid and pouredinto water. The mixture is extracted three times with 50 ml ofchloroform each time, the combined organic phases are washed five timeswith 200 ml of water each time, dried over magnesium sulphate and thesolvent is removed. After column chromatography of the crude product andsubsequent recrystallisation from ethyl acetate, there is obtained ethyl8-fluoro-11,13a-dihydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateof melting point 200°-201° C.

EXAMPLE 12

2.86 g (12.2 mol) of(S)-(+)-7-fluoro-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11-(10H)-dioneare placed in 15 ml of dry dimethylformamide and treated with 1.5 g(13.1 mmol) of potassium tert.butylate. The solution is stirred for 10minutes and cooled to -30° C. At this temperature there are addeddropwise 2.18 g (12.6 mmol) of diethylchlorophosphate and the mixture isstirred at -20° C. for 10 minutes.

Separately, 1.5 g (13.2 mmol) of potassium tert.butylate are dissolvedin 5 ml of dimethylformamide, this solution is cooled to -50° C. andtreated with 1.5 g (13.3 mmol) of ethyl isocyanoacetate. This solutionis immediately added dropwise at -20° C. to -10° C. to the mixtureobtained according to the preceding paragraph. The resulting mixture isstirred without cooling for 1 hour, neutralised with 1.2 ml of glacialacetic acid, poured into 300 ml of water and extracted three times with100 ml of ethyl acetate each time. The combined organic extracts arewashed five times with 200 ml of water each time, dried over magnesiumsulphate and evaporated. The semi-crystalline residue is recrystallisedfrom 30 ml of ethyl acetate, there being obtained ethyl(S)-7-fluoro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateof melting point 194°-195° C.

EXAMPLE 13

(a) 29.1 g (0.14 mol) of 6-chloroisatoic acid anhydride are stirred at110° C. for 1 hour with 13.12 g (0.14 mol) of sarcosine in 150 ml ofdimethyl sulphoxide. The solution obtained is concentrated and theresidue is recrystallised from alcohol. There is obtained6-chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione ofmelting point 237°-238° C.

(b) A solution of 10 g (44.5 mmol) of6-chloro-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione in 100ml of dimethylformamide is treated under an argon atmosphere with 5.50 g(49 mmol) of potassium tert.butylate and stirred for 20 minutes. Thesolution obtained is cooled to -30° C. and at this temperature 3.45 g(49 mmol) of diethylchlorophosphate are added dropwise. The mixture issubsequently stirred at -20° C. for 10 minutes.

Meanwhile, a solution of 5.50 g (40 mmol) of potassium tert.butylate in10 ml of dimethylformamide is cooled in an acetone/dry-ice bath andtreated with 5.54 g (49 mmol) of ethyl isocyanoacetate. The dark redsolution is added at -10° C. to -20° C. to the mixture obtainedaccording to the preceding paragraph and the resulting mixture isstirred without cooling for 0.5 hour before it is neutralised with 5 mlof glacial acetic acid and poured into ca 300 ml of water. The orangecoloured solution is extracted three times with chloroform. The organicphase is washed five times with water, dried over magnesium sulphate andevaporated. After chromatography and recrystallisation from ethylacetate, there is obtained ethyl7-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 229°-230° C.

EXAMPLE 14

(a) 10 g (50.6 mmol) of 6-chloroisatoic acid anhydride are stirred at110° C. for 2 hours with 5.82 g (50.6 mmol) of L-proline in 80 ml ofdimethyl sulphoxide. The solution is evaporated and the residue iscrystallised from ethyl acetate. There is obtained(S)-6-chloro-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dioneof melting point 264°-266° C.

(b) A solution of 4.0 g (16 mmol) of(S)-6-chloro-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10)-dionein 30 ml of dimethylformamide is treated under an argon atmosphere with0.57 g (16 mmol) of sodium hydride (60 percent oil dispersion) andstirred at room temperature for 1 hour. 3.02 g (17.5 mmol) ofdiethylchlorophosphate are added dropwise to the thus-obtainedsuspension at -20° C. and the mixture is stirred at this temperature for10 minutes.

Separately, a solution of 1.96 g (17.5 mmol) of potassium tert.butylatein 5 ml of dimethylformamide is cooled in an acetone/dry-ice bath andtreated with 1.92 g (17 mmol) of ethyl isocyanoacetate. This solution isadded slowly at -10° C. to -20° C. to the mixture obtained according tothe preceding paragraph. The resulting mixture is stirred withoutcooling for 0.5 hour, neutralised with 1.6 ml of acetic acid and pouredinto ca 200 ml of water. The orange coloured solution is extracted threetimes with chloroform. The organic phase is washed five times withwater, dried over magnesium sulphate and evaporated. Afterchromatography and recrystallisation from ethyl acetate, there isobtained ethyl(S)-8-chloro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateof melting point 182.5°-184° C.

EXAMPLE 15

(a) N-(2,4-dimethoxybenzyl)glycine is prepared by the reaction ofglycine with 2,4-dimethoxybenzaldehyde in the presence of sodiumhydroxide, reduction with palladium-on-carbon in methanol and subsequentneutralisation with 2 N hydrochloric acid. The aqueous solution obtainedis concentrated. 41.9 g of this mixture ofN-(2,4-dimethoxybenzyl)-glycine and sodium chloride are stirred at 110°C. for 1.5 hours in 300 ml of dimethyl sulphoxide with 23.18 g (142mmol) of isatoic acid anhydride. The mixture is poured into ca 2 litersof water and stirred for 0.5 hour. The separated crystals are filteredoff under suction, washed with water and dried. After recrystallisationfrom ethyl acetate, there is obtained3,4-dihydro-4-(2,4-dimethoxybenzyl)-2H-1,4-benzodiazepine-2,5(1H)-dioneof melting point 151°-152.5° C.

(b) A solution of 110 g (0.33 mol) of3,4-dihydro-4-(2,4-dimethoxybenzyl)-2H-1,4-benzodiazepine-2,5(1H)-dionein 330 ml of dry dimethylformamide is treated with 45.74 g (0.40 mol) ofpotassium tert.butylate. The solution is cooled to -30° C., 61 g (0.35mol) of diethylchlorophosphate are added dropwise at a temperaturebetween -30° C. and -20° C. over a period of 20 minutes and the mixtureis stirred at -20° C. for 10 minutes.

Separately, 41.6 g (0.37 mol) of potassium tert.butylate are dissolvedin 90 ml of dimethylformamide, cooled to ca -50° C. and treated with 42g (0.37 mol) of ethyl isocyanoacetate. The thus-obtained orange colouredsolution is added dropwise at -20° C. to -10° C. to the mixture obtainedaccording to the preceding paragraph. The resulting mixture is stirredfor 0.5 hour, neutralised with 33 ml of acetic acid, poured into ca 1.7liters of water and extracted three times with chloroform. The combinedchloroform phases are washed five times with water, dried over magnesiumsulphate and evaporated. After recrystallisation from ethyl acetate,there is obtained ethyl5,6-dihydro-5-(2,4-dimethoxybenzyl)-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 136°-138° C.

(c) 90 g (214 mmol) of ethyl5,6-dihydro-5-(2,4-dimethoxybenzyl)-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateare heated to reflux while stirring for 3 hours in 300 ml oftrifluoroacetic acid. After evaporation in vacuo, the residue is treatedwith water and made alkaline with 10 percent potassium carbonatesolution. The separated material is filtered off under suction, washedwith water and dried in vacuo. After recrystallisation fromchloroform/hexane, there is obtained ethyl5,6-dihydro-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate ofmelting point 248°-250° C.

EXAMPLE 16

70 mg (1.6 mmol) of sodium hydride (55 percent oil dispersion) aresuspended in 5 ml of dry dimethylformamide and treated with 135 mg (0.5mmol) of ethyl5,6-dihydro-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate.After completion of the gas evolution, 0.15 ml (2.3 mmol) of methyliodide is added and the mixture is stirred at room temperature for 1hour. The mixture is poured into ca 50 ml of water, neutralised withglacial acetic acid and extracted three times with ca 30 ml ofchloroform each time. The combined chloroform phases are washed with ca20 ml of water, dried over magnesium sulphate and evaporated. Aftercolumn chromatography and recrystallisation from ethyl acetate, there isobtained ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 166°-167° C.

EXAMPLE 17

19.0 g (0.10 mol) of3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione are placed in100 ml of dry dimethylformamide under an argon atmosphere. 15.5 g (0.12mol) of potassium tert.butylate are added thereto, the temperaturerising from 25° C. to 39° C. The mixture is cooled to room temperatureand 18.2 g (0.105 mol) of diethylchlorophosphate are added dropwise at atemperature between 18° C. and 22° C.

Separately, 11.2 g (0.10 mol) of potassium tert.butylate are dissolvedin 30 ml of dimethylformamide. This solution is cooled to ca -50° C. andtreated under argon with 11.3 g (0.10 mol) of ethyl isocyanoacetate.Subsequently, this solution is added dropwise at 18°-23° C. whilecooling to the mixture obtained according to the preceding paragraph.The resulting mixture is stirred at room temperature for 1 hour, 5 ml ofacetic acid are added, the mixture is poured into 500 ml of water andextracted twice with 200 ml of chloroform each time. The combinedchloroform extracts are washed three times with 300 ml of water eachtime, dried over magnesium sulphate and evaporated. 150 ml of ethylacetate are added to the oily residue and it is left to crystallise at0° C. The separated crystals are filtered off under suction and washedwith cold ethyl acetate, there being obtained ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate of melting point 163°-165° C. Afterrecrystallisation from 50 ml of ethyl acetate, the product melts at164°-165° C.

EXAMPLE 18

(a) 21.5 g (75.4 mmol) of ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateare dissolved in 250 ml of hot absolute tetrahydrofuran (filtered overAlox basic I) under an argon atmosphere while stirring, cooled to ca 30°C. and treated dropwise with a solution of 1.66 g (75.4 mmol) of lithiumborohydride in 25 ml of absolute tetrahydrofuran. The mixture is heatedto boiling under reflux for 6 hours, cooled to room temperature anddecomposed with 50 ml of 3 N aqueous hydrochloric acid. The mixture isstirred at 60° C. for a further 2 hours and the tetrahydrofuran isremoved in vacuo. The residue is made alkaline with concentrated ammoniaand left to stand in an ice-bath for 2 hours. The crude product isfiltered off under suction, washed with a large amount of water andrecrystallised from ethanol. There is obtained4,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-oneof melting point 224°-226° C.

(b) A mixture of 12.2 g (50 mmol) of4,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one,80.0 g of manganese dioxide and 500 ml of absolute methylene chloride isstirred at room temperature for 1 hour under an argon atmosphere andsubsequently the manganese dioxide is filtered off under suction overDicalit while rinsing with methylene chloride. The filtrate isevaporated to dryness in vacuo. After warming the residue in ca 150 mlof ethyl acetate, there is obtained5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehydeof melting point 205°-207° C.

(c) A solution of 10.6 g (37.3 mmol) of sodium carbonate decahydrate in40 ml of water is added dropwise to a suspension of 7.2 g (29.8 mmol) of5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehydeand 2.53 g (37.3 mmol) of hydroxylamine hydrochloride in 250 ml ofwater. The mixture is stirred at 70° C. for 6 hours and cooled to roomtemperature. The separated crude product is filtered off under suction,washed with water and recrystallised while still moist from ca 60 ml ofdimethylformamide. There is thus obtained5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde-3-oximeof melting point 268°-274° C. (decomposition).

(d) A solution of 4.8 g (18.7 mmol) of5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehyde-3-oximein 50 ml of acetic acid anhydride is heated to boiling under reflux for28 hours. After evaporation of the mixture in vacuo, the residue istaken up in 150 ml of chloroform and washed twice with 30 ml ofsaturated sodium hydrogen carbonate solution each time and with 30 ml ofwater. The organic phase is dried over magnesium sulphate andevaporated. After column chromatography on silica gel andrecrystallisation from ethyl acetate, there is obtained5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carbonitrileof melting point 184°-186° C.

EXAMPLE 19

(a) 1.22 g (50.2 mmol) of magnesium shavings are covered with 60 ml ofabsolute diethyl ether under an argon atmosphere and treated with 2-3drops of ethyl iodide. When the Grignard reaction starts, a solution of4.3 ml (51 mmol) of ethyl iodide in 10 ml of absolute diethyl ether isadded dropwise at the boiling point. After the magnesium has dissolvedcompletely, the mixture is treated dropwise with a solution, warmed to30° C., of 0.65 g (40 mmol) of5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxaldehydein 200 ml of absolute tetrahydrofuran. The yellow coloured suspension isheated to boiling under reflux for ca 5.5 hours, cooled to roomtemperature and poured into 600 ml of ice/water. The mixture is filteredover Dicalit while rinsing with tetrahydrofuran. After concentration ofthe filtrate in vacuo, the residue is taken up in 250 ml of chloroform.The chloroform phase is washed twice with 60 ml of water each time,dried over magnesium sulphate and concentrated. The crude product ischromatographed on silica gel using chloroform/methanol (19:1, vol/vol)for the elution. Afte recrystallisation from ca 40 ml of ethyl acetate,there is obtained4,5-dihydro-3-(1-hydroxypropyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-oneof melting point 145°-147° C.

(b) A mixture of 1.84 g (6.8 mmol) of4,5-dihydro-3-(1-hydroxypropyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one,16 g of manganese dioxide and 150 ml of methylene chloride is stirred atroom temperature under an argon atmosphere for 2 hours. The manganesedioxide is filtered off under suction over a glass filter and thefiltrate is evaporated in vacuo. After recrystallisation of the residuefrom 100 ml of ethyl acetate, there is obtained4,5-dihydro-5-methyl-3-propionyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-oneof melting point 215°-216° C.

EXAMPLE 20

(a) A mixture of 910 ml of diethyl malonate and 3.0 liters oftetrahydrofuran is cooled to 0° C. while stirring under argon andtreated portionwise with 350 g of sodium hydride (55 percent oildispersion) in such a manner that the temperature does not exceed 15° C.Thereafter, the mixture is stirred at room temperature overnight, cooledto 0°-5° C. and 290 ml of diethylchlorophosphate are added dropwise overa period of 15 minutes. After a further 2 hours at room temperature, themixture is treated slowly with a suspension, warmed to ca 45° C., of 190g of 4-methyl-3H-1,4-benzodiazepine-2,5(1H,4H)-dione in 2 liters oftetrahydrofuran, the addition taking ca 1 hour. The mixture is stirredat room temperature overnight, cooled to 5° C. and treated dropwise with350 ml of glacial acetic acid. There is thus obtained a thick slurrywhich is again made well stirrable by the addition of 500 ml of water.The tetrahydrofuran is distilled off from the mixture and the partiallycrystalline residue is partitioned between ether and water. The organicphase is washed with water, dried and concentrated. The red-browncoloured residue is dissolved in 2 liters of boiling n-hexane and thencooled. The mixture is left to stand at 2° C. overnight and theresulting crystallisate is filtered off under suction. The light yellowcrystals are subsequently dissolved in 800 ml of hot toluene andcrystallised by the addition of 600 ml of n-hexane and scratching. Afterstanding in the cold overnight, the crystals are filtered off undersuction and dried at 50° C. in vacuo. There is obtained diethyl(1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene)malonatein the form of white crystals of melting point 139° C.

(b) A mixture of 33.2 g (0.1 mol) of diethyl(1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene)malonate,8.0 g (0.2 mol) of sodium hydroxide and 400 ml of absolute ethanol isheated to reflux for 3 hours. The mixture is subsequently left tocrystallise at 0° C. and the separated solid material is filtered offunder suction and transferred to a separating funnel. 100 ml ofchloroform and 25 ml of water are added thereto. Then, the aqueous phaseis separated. The organic phase is washed with 25 ml of water, driedover sodium sulphate and evaporated. There is obtained crystalline ethyl(1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene)acetateof melting point 154°-155° C.

(c) 32.2 g (0.124 mol) of ethyl(1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene)acetateare dissolved in 300 ml of acetic acid and treated at room temperaturewith 12.8 g (0.186 mol) of sodium nitrite. The mixture is stirred atroom temperature for a further 10 minutes, then poured into 1 liter ofwater and extracted three times with 200 ml of chloroform each time. Thecombined chloroform phases are washed with 100 ml of water, dried overmagnesium sulphate and evaporated. The residue is recrystallised fromethyl acetate. There is obtained ethyl4,5-dihydro-4-methyl-5-oxo-3H-1,4-benzodiazepine-2-glyoxylate α-oxime ofmelting point 173°-174° C.

(d) 4.34 g (15 mmol) of ethyl4,5-dihydro-4-methyl-5-oxo-3H-1,4-benzodiazepine-2-glyoxylate α-oximeare dissolved in 60 ml of tetrahydrofuran, treated with 30 ml of ethanoland 1.0 g of 5% palladium-on-carbon and hydrogenated at normal pressureand room temperature. After uptake of the theoretical amount of hydrogen(1 hour), the catalyst is filtered off and the filtrate is evaporated invacuo. There is thus obtained ethylα-amino-1,3,4,5-tetrahydro-5-oxo-2H-1,4-benzodiazepin-2-ylidene-acetatein the form of a pale yellow oil which is sensitive to oxidation.

(e) 4.1 g of ethylα-amino-1,3,4,5-tetrahydro-5-oxo-2H-1,4-benzodiazepin-2-ylidene-acetateare dissolved in 25 ml of ethyl acetate, treated with 3.1 ml (18.1 mmol)of N,N-dimethylformamide diethyl acetal and heated to boiling underreflux for 0.5 hour. After cooling, the separated material is filteredoff under suction and recrystallised form ethanol. After chromatographyof the mother liquor, there is obtained a second portion of ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof the same purity; melting point 166°-168° C.

EXAMPLE 21

1.10 g of ethylα-amino-1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene-acetateare dissolved in 15 ml of toluene and treated with 1.0 ml of triethylorthoformate. The mixture is heated to reflux for 50 minutes,subsequently cooled and evaporated in vacuo. The crystalline residue issuspended in 25 ml of ethyl acetate, filtered off and dried. There isobtained ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 165° C.

EXAMPLE 22

(a) 1.10 g of ethylα-amino-1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene-acetateare dissolved in 20 ml of methylene chloride, treated with 0.65 ml of 37percent aqueous formaldehyde solution and stirred at room temperaturefor 30 minutes. The mixture is washed three times with 10 ml of watereach time. The organic phase is separated, dried and evaporated invacuo. The residue is dissolved in ethyl acetate and decolourised withactive carbon. After filtration of the carbon and concentration of thefiltrate, a light yellow oil is obtained.

(b) The foreoing oil is dissolved in 10 ml of methylene chloride andstirred at room temperature for 30 minutes together with 3.5 g ofmanganese dioxide. After filtration of the suspension while rinsing withmethylene chloride, the filtrate is evaporated in vacuo. There isobtained a yellow coloured oil which, after the addition of ethylacetate and ether, yields crystalline ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 162°-164° C.

EXAMPLE 23

1.0 g of ethylα-amino-1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene-acetateare dissolved in 20 ml of methylene chloride, treated with 0.65 ml of 37percent aqueous formaldehyde solution and stirred in the presence of airat room temperature for 2 hours. The solution is subsequently washedtwice with 10 ml of water each time. The organic phase is separated,dried and decolourised with active carbon. After filtration of thecarbon, the filtrate is evaporated in vacuo and the residue ischromatographed on 20 g of silica gel. Elution is carried out firstlywith chloroform and subsequently with chloroform/ethanol (985:15). Thefractions which contain ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateas the main component are combined and evaporated in vacuo. The residueis dissolved in ethanol and crystallised by the addition of diisopropylether. There is obtained ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 162°-164° C.

EXAMPLE 24

285 mg (1 mmol) of ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateand 66 mg of potassium cyanide are heated to boiling under reflux for 24hours in 10 ml of methanol. Then, the mixture is concentrated on arotary evaporator, the residue is partitioned between water andchloroform, extracted twice with chloroform, the chloroform phase isdried over magnesium sulphate and evaporated. There is obtained methyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 212°-214° C. This product is uniform according tothin-layer chromatography.

EXAMPLE 25

285 mg (1 mmol) of ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateand 50 mg of potassium cyanide are stirred at 60° C. for 72 hours in 10ml of 2-propanol. Then, the mixture is concentrated on a rotaryevaporator, the residue is partitioned between water and chloroform,extracted twice with chloroform, the chloroform phase is dried overmagnesium sulphate and evaporated. There is obtained isopropyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine3-carboxylate of melting point 190°-192° C. This product is uniformaccording to thin-layer chromatography.

EXAMPLE 26

A mixture of 1.42 g (5 mmol) of ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,100 mg of potassium cyanide and 10 ml of ethyleneglycol is stirred at130° C. for 6 hours, subsequently diluted with chloroform, washed withwater, dried over magnesium sulphate and evaporated. Afterrecrystallisation of the residue from ethyl acetate, there is obtained2-hydroxyethyl-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 222°-223° C.

EXAMPLE 27

670 mg (2.3 mmol) of ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateand 497 mg (1.23 mmol) of2,4-bis(p-methoxyphenyl)-1,3,2,4-dithiadiphosphentane-2,4-disulphide areheated to boiling under reflux for 2.5 hours in 5 ml of absolutetoluene. The mixture is chromatographed on silica gel with ethyl acetateand there is obtained ethyl5,6-dihydro-5-methyl-6-thioxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 164°-165° C.

EXAMPLE 28

(a) A mixture of 14.0 g (79 mmol) of 6-methylisatoic acid anhydride,7.04 g (79 mmol) of sarcosine and 80 ml of dimethyl sulphoxide isstirred at 110° C. for 3 hours. The red coloured solution is evaporatedin a high vacuum. The residue is treated with 80 ml of ethanol, theproduct crystallising out. There is obtained3,4-dihydro-4,6-dimethyl-2H-1,4-benzodiazepine-2,5(1H)-dione of meltingpoint 200°-202° C.

(b) A solution of 9 g (44 mmol) of3,4-dihydro-4,6-dimethyl-2H-1,4-benzodiazepine-2,5(1H)-dione in 100 mlof dimethylformamide is treated with 1.69 g of sodium hydride (60percent oil dispersion) and stirred for 1 hour. The thus-obtainedsuspension is treated dropwise at -20° C. with 7.59 g (44 mmol) ofdiethylchlorophosphate. Subsequently, the mixture is stirred at thistemperature for a further 10 minutes.

Separately, a solution of 5.60 g (50 mmol) of potassium tert.butylate in10 ml of dimethylformamide is cooled in an acetone/dry-ice bath andtreated with 5.65 g (50 mmol) of ethyl isocyanoacetate. This solution isadded dropwise at -10° C. to -20° C. to the mixture obtained accordingto the preceding paragraph. The resulting mixture is stirred withoutcooling for a further 0.5 hour, neutralised with 5 ml of acetic acid andpoured into ca 300 ml of water. The orange coloured solution isextracted three times with chloroform. The organic phase is washed fivetimes with water, dried over magnesium sulphate and evaporated. Afterrecrystallisation of the residue from alcohol and ether, there isobtained ethyl5,6-dihydro-5,7-dimethyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 146°-147° C.

EXAMPLE 29

(a) A solution of 13.6 g (0.0768 mol) of 6-methylisatoic acid anhydrideand 8.8 g (0.0768 mol) of L-proline is heated at 110° C. for 1 hour in75 ml of dimethyl sulphoxide. Subsequently, the mixture is evaporated todryness in a high vacuum and the residue is recrystallised from ethylacetate with the addition of active carbon. There is obtained(S)-1,2,3,11a-tetrahydro-6-methyl-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dioneof melting point 212°-214° C.

(b) A solution of 5.76 g (25 mmol) of(S)-1,2,3,11a-tetrahydro-6-methyl-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dionein 40 ml of dimethylformamide is treated under an argon atmosphere with0.9 g (25 mmol) of sodium hydride (60 percent oil dispersion) andstirred for 1 hour. 4.23 g (25 mmol) of diethylchlorophosphate are addeddropwise at -20° C. to the solution obtained and the mixture is stirredat this temperature for 10 minutes.

Separately, a solution of 2.80 g (25 mmol) of potassium tert.butylate in7 ml of dimethylformamide is cooled in an acetone/dry-ice bath andtreated with 2.32 g (25 mmol) of ethyl isocyanoacetate. This solution isadded dropwise at -10° C. to -20° C. to the mixture obtained accordingto the preceding paragraph. Subsequently, the cooling bath is removed,the mixture is stirred for 0.5 hour, neutralised with 2.5 ml of aceticacid and poured into ca 250 ml of water. The orange coloured solution isextracted three times with chloroform, the organic phase is washed fivetimes with water, dried over magnesium sulphate and evaporated. Aftercolumn chromatography and recrystallisation from ethyl acetate/hexane,there is obtained ethyl(S)-11,12,13,13a-tetrahydro-8-methyl-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c]benzodiazepine-1-carboxylateof melting point 152°-153° C.

EXAMPLE 30

A solution of 21.6 g (0.10 mol) of(S)-(+)-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dionein 100 ml of dry dimethylformamide is treated under an argon atomspherewith 13.5 g (0.12 mol) of potassium tert.butylate, the temperaturerising from 24° C. to 46° C. The mixture is cooled to room temperatureand 18.2 g (0.105 mol) of diethylchlorophosphate are added dropwise at atemperature between 18° C. and 23° C.

Separately, 11.2 g (0.10 mol) of potassium tert.butylate are dissolvedin 30 ml of dimethylformamide. This solution is cooled to ca -50° C. andtreated under argon with 11.3 g (0.10 mol) of ethyl isocyanoacetate.Subsequently, this solution is added dropwise at 18°-23° C. whilecooling to the mixture obtained according to the preceding paragraph.The resulting mixture is stirred at room temperature for 1 hour, 5 ml ofacetic acid are added thereto, then the mixture is poured into 500 ml ofwater and extracted twice with 200 ml of chloroform each time. Thecombined chloroform phases are washed three times with 300 ml of watereach time, dried over magnesium sulphate and evaporated. 150 ml ofacetic acid are added to the oily residue and it is left to crystalliseat 0° C. The separated crystals are filtered off under suction andwashed with cold ethyl acetate, there being obtained ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate of melting point 196°-197° C.The mother liquor is evaporated and the residue is dissolved in 50 ml ofethyl acetate. A further portion of the foregoing product (melting point195°-196° C.) crystallises from the solution.

EXAMPLE 31

A mixture of 311 mg (1 mmol) of ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,66 mg of potassium cyanide and 10 ml of absolute methanol is heated toboiling under reflux for 6 hours. The mixture is concentrated, a smallamount of water is added, the mixture is extracted three times with 10ml of chloroform each time, dried over magnesium sulphate, evaporatedand recrystallised from ethyl acetate/hexane. There is obtained methyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateof melting point 165°-167° C.

EXAMPLE 32

A mixture of 5.0 g (0.0161 mol) of ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateand 3.46 g (0.0086 mol) of2,4-bis(p-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulphide isheated to boiling under reflux for 1.5 hours with 30 ml of toluene. Thissolution is chromatographed on silica gel using ethyl acetate for theelution. There is obtained ethyl(S)-11,12,13,13a-tetrahydro-9-thioxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylatewhich is recrystallised from 180 ml of ethyl acetate and then melts at227°-229° C.

EXAMPLE 33

934 mg (3 mmol) of ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateare stirred at 60° C. for 48 hours with 198 mg (3 mmol) of potassiumcyanide in 30 ml of dry 2-propanol. The mixture is evaporated in vacuo.The residue is treated with 30 ml of 2-propanol and 198 mg (3 mmol) ofpotassium cyanide and heated to boiling under reflux for 22 hours. Afterevaporation in vacuo, the residue is treated with water and extractedthree times with 30 ml of chloroform each time. The combined chloroformphases are washed three times with 20 ml of water each time, dried overmagnesium sulphate and evaporated. After recrystallisation from ethylacetate/n-hexane, there is obtained isopropyl(S)-11,13,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateof melting point 207°-208° C.

EXAMPLE 34

(a) A mixture of 175 g (0.93 mol) of methyl3-amino-2-thiophenecarboxylate hydrochloride, 1.8 liters of n-butanoland 77 g of sodium hydroxide is heated to boiling under reflux for 30minutes. After concentration of the resulting suspension on a rotaryevaporator, the mixture of sodium 3-amino-2-thiophenecarboxylate andsodium chloride is used directly in the next step. For this purpose, themixture is treated with 800 ml of water, 280 ml of concentratedhydrochloric acid and 230 ml of tetrahydrofuran. Phosgene is conductedthrough this mixture at 15°-25° C. for 2.5 hours and then air isconducted through for 15 minutes. The separated solid material isfiltered off under suction, washed with water and dried. There isobtained 2H-thieno[3,2-d][1,3]-oxazine-2,4(1H)-dione of melting point220°-221° C.

(b) A solution of 34.3 g (202 mmol) of2H-thieno[3,2-d][1,3]oxazine-2,4(1H)-dione and 23.3 g (202 mmol) ofL-proline is stirred at 110° C. for 1 hour in 200 ml of dimethylsulphoxide. The brown coloured solution obtained is poured into 2 litersof water and stirred at room temperature overnight. The separatedproduct is filtered off under suction, dried on a rotary evaporator andwashed with ca 200 ml of boiling ethyl acetate. There is thus obtained(S)-5a,6,7,8-tetrahydro-5H-pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-5,10(4)-dioneof melting point 244°-247° C.

(c) 7 g (31.5 mmol) of(S)-5a,6,7,8-tetrahydro-5H-pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-5,10(4)-dioneare suspended in 30 ml of dimethylformamide under an argon atmosphereand treated at -50° C. with 3.92 g (35 mmol) of potassium tert.butylate.The solution is stirred for 10 minutes at -50° C., 6.0 g (35 mmol) ofdiethylchlorophosphate are added dropwise at this temperature and themixture is stirred for 0.5 hour.

Separately, 3.92 g (35 mmol) of potassium tert.butylate, dissolved in 7ml of dimethylformamide, are cooled in an acetone/dry-ice bath andtreated with 3.95 g (35 mmol) of ethyl isocyanoacetate. The orangecoloured solution obtained is added dropwise at -50° C. to the mixtureobtained according to the preceding paragraph. Subsequently, the mixtureis stirred at -50° C. to -60° C. for a further 10 minutes, neutralisedwith 3.2 ml of acetic acid and poured into ca 250 ml of water. Themixture is extracted twice with 200 ml of chloroform each time, thecombined chloroform phases are washed five times with 300 ml of watereach time, dried over magnesium sulphate and evaporated. After columnchromatography and recrystallisation from ethyl acetate, there isobtained ethyl(S)-10,11,12,12a-tetrahydro-8-oxo-8H-imidazo[5,1-c]pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-1-carboxylateof melting point 212.5°-213° C.

EXAMPLE 35

1.50 g of ethyl(S)-10,11,12,12a-tetrahydro-8-oxo-8H-imidazo[5,1-c]pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-1-carboxylateare stirred at 50° C. for 20 hours together with 100 g of powderedpotassium cyanide in 10 ml of methanol. The solution is concentrated andthe residue is taken up in chloroform. The insoluble material isfiltered off under suction and the filtrate is evaporated. Afterrecrystallisation of the residue from chloroform/hexane, there isobtained methyl(S)-10,11,12,12a-tetrahydro-8-oxo-8H-imidazo[5,1-c]pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-1-carboxylateof melting point 192°-193° C.

EXAMPLE 36

(a) A mixture of 30.0 g (177 mmol) of2H-thieno[3,2-d][1,3]-oxazine-2,4(1H)-dione and 17.3 g (195 mmol) ofsarcosine in 100 ml of dimethyl sulphoxide is stirred at 110° C. for 1.5hours. The dark brown coloured solution is poured into ca 600 ml ofice/water. The separated oil is taken up in ca 200 ml of ethyl acetateand the aqueous phase is evaporated in vacuo until crystallisationbegins. The mixture is cooled in an ice-bath for ca 3 hours and theseparated material is filtered off under suction and washed with a smallamount of water. After drying on a rotary evaporator, there is obtained3,4-dihydro-4-methyl-2H-thieno[3,2-e][1,4]diazepine-2,5(1H)-dione ofmelting point 270°-272° C.

(b) A suspension, cooled to 15° C., of 4.8 g (24.5 mmol) of3,4-dihydro-4-methyl-2H-thieno[3,2-e][1,4]diazepine-2,5(1H)-dione in 30ml of dimethylformamide is treated under an argon atmosphere with 3.28 g(29.4 mmol) of potassium tert.butylate. After cooling the dark browncoloured solution to -40° C., 3.7 ml (25.7 mmol) ofdiethylchlorophosphate are added dropwise at -40° C. to -30° C. Thecooling bath is removed and the mixture is stirred for 20 minutes, thetemperature rising to -15° C.

Separately, 3.0 g (27 mmol) of potassium tert.butylate are dissolved in8 ml of dimethylformamide, cooled in an acetone/dry-ice bath and treatedwith 3.1 ml (27 mmol) of ethyl isocyanoacetate. The orange colouredsolution is added dropwise at -15° C. to -10° C. to the mixture obtainedaccording to the preceding paragraph. After removal of the cooling bath,the mixture is stirred until the temperature has risen to 20° C.Subsequently, the mixture is neutralised with 2 ml of acetic acid,poured into ca 150 ml of water and extracted three times with 150 ml ofchloroform each time. The combined chloroform phases are washed threetimes with 100 ml of saturated sodium chloride solution each time, driedover magnesium sulphate and evaporated in vacuo. After columnchromatography and recrystallisation from ethyl acetate/n-hexane, thereis obtained ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a]thieno[2,3-f][1,4]diazepine-3-carboxylateof melting point 160°-162° C.

EXAMPLE 37

A suspension of 430 mg (1.5 mmol) of ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a]thieno[2,3-f][1,4]-diazepine-3-carboxylateand 99 mg (1.5 mmol) of potassium cyanide in 15 ml of absolute methanolis heated under reflux for 3 hours while stirring. After evaporation invacuo, the residue is treated with ca 20 ml of ice/water and extractedthree times with ca 30 ml of chloroform each time. The combinedchloroform phases are washed twice with ca 20 ml of water each time,dried over magnesium sulphate and evaporated. After washing with boilingethyl acetate, there is obtained methyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a]thieno[2,3-f][1,4]diazepine-3-carboxylateof melting point 244°-245° C.

EXAMPLE 38

A solution of 16.85 g (0.075 mol) of3,4-dihydro-7-chloro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione in 150ml of tetrahydrofuran is treated under an argon atmosphere with 8.98 g(0.08 mol) of potassium tert.butylate, cooled to -10° C., 12.94 g (0.08mol) of diethylchlorophosphate are added dropwise and the mixture isstirred at -10° C. for 20 minutes.

Separately, 8.98 g (0.08 mol) of potassium tert.butylate are dissolvedin 30 ml of dimethylformamide. This solution is treated under argon atca -50° C. with 9.05 g (0.08 mol) of ethyl isocyanoacetate.Subsequently, this solution is added dropwise to the mixture obtainedaccording to the preceding paragraph. The resulting mixture is stirredat room temperature for 1 hour, 5 ml of acetic acid are added, themixture is poured into 500 ml of water and extracted three times with200 ml of chloroform each time. The combined chloroform extracts arewashed twice with 200 ml of water each time, dried over magnesiumsulphate and evaporated. 75 ml of ethyl acetate are added to the residueand it is left to crystallise at 0° C. The separated crystals arefiltered off under suction, washed with cold ethyl acetate andrecrystallised from 125 ml of ethyl acetate. There is thus obtainedethyl8-chloro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 188°-189° C.

EXAMPLE 39

A solution of 35 g (0.14 mol) of(S)-(+)-7-chloro-1,2,3,11a-tetrahydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dionein 170 ml of dry dimethylformamide is treated under an argon atmospherewith 17.3 g (0.15 mol) of potassium tert.butylate, the temperaturerising from 24° C. to 40° C. The mixture is cooled to -30° C. and 25 g(0.15 mol) of diethylchlorophosphate are added dropwise at a temperaturebetween -30° C. and -20° C.

Separately, 16.8 g (0.15 mol) of potassium tert.butylate are dissolvedin 50 ml of dimethylformamide. This solution is cooled to ca -50° C. andtreated under argon with 17.42 g (0.15 mol) of ethyl isocyanoacetate.Subsequently, this solution is added dropwise at -20° C. to -10° C. tothe mixture obtained according to the preceding paragraph. The resultingmixture is stirred without cooling for 1 hour, 14 ml of acetic acid areadded, the mixture is subsequently poured into ca 1000 ml of water andextracted three times with 250 ml of chloroform each time. The combinedchloroform phases are washed five times with 300 ml of water each time,dried over magnesium sulphate and evaporated. The residue isrecrystallised from 500 ml of ethyl acetate. There is obtained ethyl(S)-(+)-7-chloro-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateof melting point 242°-244° C.

EXAMPLE 40

(a) A solution of 39.5 g of 5-bromoisatoic acid anhydride and 14.5 g ofsarcosine in 150 ml of dimethyl sulphoxide is heated to 100° C. whilestirring. In so doing, a vigorous evolution of carbon dioxide occursfrom 70° C. and this has finished after ca 30 minutes. The mixture isstirred at 100° C. for a further 30 minutes and thereafter the mixtureis poured into 900 ml of ice-water (temperature 5° C.) and the separatedmaterial is filtered off under suction. The crystals are washed withwater and subsequently dried at 50° C. over phosphorus pentoxide in avacuum drying cabinet. There is obtained7-bromo-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione in theform of light beige crystals. A sample recrystallised from methanol hasa melting point of 260°-261° C.

(b) A solution of 17 g (63 mmol) of7-bromo-3,4-dihydro-4-methyl-2H-1,4-benzodiazepine-2,5(1H)-dione in 100ml of dimethylformamide is treated under an argon atmosphere with 7.5 g(67 mmol) of potassium tert.butylate. The solution obtained is treateddropwise at -30° C. with 11.56 g (67 mmol) of diethylchlorophosphate andthe mixture is stirred at -20° C. for 10 minutes.

Separately, a solution of 7.5 g (67 mmol) of potassium tert.butylate in30 ml of dimethylformamide is cooled in an acetone/dry-ice bath andtreated with 7.58 g (67 mmol) of ethyl isocyanoacetate. This solution isadded at -10° C. to -20° C. to the mixture obtained according to thepreceding paragraph. The cooling bath is removed, the mixture is stirredfor 0.5 hour, neutralised with 8 ml of acetic acid and poured into ca600 ml of water. The orange coloured solution is extracted three timeswith chloroform. The organic phase is washed five times with water,dried over magnesium sulphate and evaporated. After recrystallisationfrom ethyl acetate, there is obtained8-bromo-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 194°-195° C.

EXAMPLE 41

(a) A suspension of 12.2 g (0.063 mol) of3-carbomethoxy-4-aminothiophene hydrochloride in 100 ml of methylenechloride is treated with 10 ml (0.126 mol) of chloroacetyl chloride andsubsequently dropwise with 17.6 ml (0.126 mol) of triethylamine, thetemperature being held below 25° C. The solution is poured into waterand extracted twice with 50 ml of methylene chloride each time. Thecombined methylene chloride extracts are washed three times with 50 mlof water each time, dried over magnesium sulphate and evaporated. Afterchromatography on silica gel using methylene chloride for the elution,there is obtained crystalline3-carbomethoxy-4-[(chloroacetyl)amino]thiophene of melting point98°-100° C.

(b) A solution of 13.25 g (0.057 mol) of3-carbomethoxy-4-[(chloroacetyl)amino]thiophene in a mixture of 60 ml ofdimethylformamide and 60 ml of toluene is treated with 15.7 g ofpotassium carbonate and 0.05 g of potassium iodide and the mixture iswarmed at 50° C. with constant introduction of methylamine. After 1hour, the mixture is poured into ice/water and extracted three timeswith toluene. The combined toluene phases are washed twice with water,dried over magnesium sulphate and evaporated. The crude product ischromatographed on silica gel using chloroform for the elution. There isthus obtained 3-carbomethoxy-4-[[(methylamino)acetyl]amino] thiophene inthe form of an oil. The corresponding hydrochloride melts at 234°-236°C. (decomposition).

(c) 9.5 g (0.036 mol) of 3-carbomethoxy-4[[(methylamino)acetyl]amino]thiophene are heated at 250° C. in 2 g portions for 5 minutes under aprotective gas and while stirring. The crude products from the variousbatches are washed together with methanol and concentrated. Afterrepeated fractional crystallisation from dimethylformamide/ether, thereis obtained pure3,4-dihydro-4-methyl-5H-thieno[3,4-e][1,4]diazepine-2,5(1H)-dione ofmelting point 263°-265° C.

(d) A mixture of 1.90 g (9.7 mmol) of3,4-dihydro-4-methyl-5H-thieno[3,4-e][1,4]diazepine-2,5(1H)-dione and 15ml of dimethylformamide is treated under argon with 0.35 g (9.7 mmol) ofsodium hydride (60 percent oil dispersion) and stirred for 1 hour. 1.40ml (9.7 mmol) of diethylchlorophosphate are added dropwise to thissolution at -30° C. The mixture is stirred at -20° C. for 10 minutes.

Separately, a solution of 1.08 g (9.7 mmol) of potassium tert.butylatein 3 ml of dimethylformamide is cooled to -50° C. and treated with 1.09g (9.7 mmol) of ethyl isocyanoacetate. This solution is added dropwiseat -10° C. to -20° C. to the mixture obtained according to the precedingparagraph and the resulting mixture is stirred for 0.5 hour. The mixtureis neutralised with 1 ml of acetic acid, poured into ca 200 ml of waterand extracted three times with chloroform. The combined chloroformphases are washed five times with water, dried over magnesium sulphateand evaporated. After column chromatography of the crude product andrecrystallisation from ethyl acetate, there is obtained ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a]thieno[3,4-f][1,4]diazepine-3-carboxylateof melting point 207.5°-208.5° C.

EXAMPLE 42

(a) A solution of 46.7 g (150 mmol) of ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylatein 300 ml of dry tetrahydrofuran is treated dropwise at ca 35° C. with asolution of 8.3 g (377 mmol) of lithium borohydride in 110 ml of drytetrahydrofuran. The mixture is heated to boiling under reflux for ca 40hours, cooled to room temperature, treated with 110 ml of 12 percenthydrochloric acid and 20 ml of concentrated hydrochloric acid and againheated to boiling under reflux for 2 hours. After removal of thetetrahydrofuran in vacuo, the residue is made alkaline with concentratedammonia. The separated material is filtered off under suction and washedwith water. After recrystallisation from ethanol, there is obtained(S)-11,12,13,13a-tetrahydro-1-(hydroxymethyl)-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepin-9-oneof melting point 212°-214° C.

(b) A suspension of 12.1 g (45 mmol) of(S)-11,12,13,13a-tetrahydro-1-(hydroxymethyl)-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepin-9-onein 300 ml of methylene chloride is treated with 70 g of manganesedioxide and stirred at room temperature for ca 0.75 hour. Afterfiltration over Dicalit, the filtrate is evaporated in vacuo and theresidue is washed with ca 100 ml of boiling ethyl acetate. There isobtained(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxaldehydeof melting point 206°-208° C.

(c) A suspension of 2.67 g (10 mmol) of(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxaldehydeand 0.85 g (12.5 mmol) of hydroxylamine hydrochloride in 60 ml of wateris treated dropwise at room temperature with a solution of 3.57 g (12.5mmol) of sodium carbonate decahydrate in 10 ml of water. The mixture isstirred at 70° C. for 4 hours. After cooling, the separated material isfiltered off under suction, washed with water and recrystalliseddirectly from 50 ml of dimethylformamide. There is obtained(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxaldehyde-1-oximeof melting point 285° C.

(d) A solution of 5.24 g (18.5 mmol) of(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxaldehyde-1-oximein 50 ml of acetic acid anhydride is heated to boiling under reflux for3 hours and subsequently evaporated in vacuo. The residue is taken up inchloroform, the solution is washed once with ca 30 ml of saturatedsodium hydrogen carbonate solution and once with ca 30 ml of water,dried over magnesium sulphate and evaporated. After columnchromatography and recrystallisation from ethyl acetate, there isobtained(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carbonitrileof melting point 223°-225° C.

EXAMPLE 43

A mixture of 1.92 g (9 mmol) of(S)-3,11a-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5-11(10H)-dioneand 15 ml of dimethylformamide is treated with 0.33 g (9 mmol) of sodiumhydride (60 percent oil dispersion) and stirred for 0.5 hour. 155 g (9mmol) of diethylchlorophosphate are added dropwise thereto at -30° C.and the mixture is stirred at -20° C. for 10 minutes.

Separately, a solution of 1 g (9 mmol) of potassium tert.butylate in 3ml of dimethylformamide is cooled to ca -45° C. and treated with 1.02 g(9 mmol) of ethyl isocyanoacetate. The orange coloured solution obtainedis added dropwise at -20° C. to -10° C. to the mixture obtainedaccording to the preceding paragraph and the resulting mixture isstirred without cooling for 0.5 hour. Subsequently, the mixture isneutralised with 1 ml of acetic acid, poured into water and extractedthree times with chloroform. The combined chloroform extracts are washedfive times with water, dried over magnesium sulphate and evaporated.After chromatography of the crude product and recrystallisation of theresulting material from ethyl acetate/hexane, there is obtained ethyl(R,S)-11,13a-dihydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateof melting point 184°-185.5° C.

EXAMPLE 44

A mixture of 3.12 g (10 mmol) of ethyl(S)-10,11,12,12a-tetrahydro-8-oxo-8H-imidazo[5,1-c]pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-1-carboxylate,80 mg of powdered potassium cyanide and 30 ml of ethyleneglycol isstirred at 100° C. overnight. After removal of the ethyleneglycol, theresidue is purified by column chromatography. There is obtained2-hydroxyethyl(S)-10,11,12,12a-tetrahydro-8-oxo-8H-imidazo[5,1-c]pyrrolo[1,2-a]thieno[3,2-e][1,4]diazepine-1-carboxylateof melting point 182°-184° C.

EXAMPLE 45

(a) A solution of 2.32 g (10 mmol) of(2R,11aS)-1,2,3,11a-tetrahydro-2-hydroxy-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dionein 20 ml of pyridine is treated with 0.86 ml (11 mmol) ofmethanesulphonyl chloride and stirred at room temperature for 4 hours.After evaporation in vacuo, the residue is treated with water andextracted three times with ca 60 ml of chloroform each time. Thecombined chloroform extracts are washed twice with ca 30 ml of watereach time, dried over magnesium sulphate and evaporated. Afterrecrystallisation from ethanol, there is obtained(2R,11aS)-2,3,5,10,11,11a-hexahydro-5,11-dioxo-1H-pyrrolo[2,1-c][1,4]benzodiazepin-3-ylmethanesulphonate of melting point 179°-181° C.

(b) A suspension of 5.92 g (135.7 mmol) of sodium hydride (55 percentoil dispersion) in 150 ml of dry dimethylformamide is treated with 17.0g (54.8 mmol) of(2R,11aS)-2,3,5,10,11,11a-hexahydro-5,11-dioxo-1H-pyrrolo[2,1-c][1,4]benzodiazepin-3-ylmethanesulphonate and stirred at room temperature for ca 16 hours and at40° C. for ca 16 hours. The mixture is treated with water, poured intoca 300 ml of ice/water, neutralised with glacial acetic acid and left tostand in an ice/bath for 2 hours. The separated material is filtered offunder suction, washed with water and recrystallised from dioxan. Thereis thus obtained(R,S)-1,11a-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dioneof melting point 236°-238° C.

(c) A suspension of 1.01 g (23.2 mmol) of sodium hydride (55 percent oildispersion) in 35 ml of dry dimethylformamide is treated with 4.15 g(19.4 mmol) of(R,S)-1,11a-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11(10H)-dione.After completion of the gas evolution, the mixture is cooled to -40° C.and treated dropwise with 3.1 ml (20.2 mmol) of diethylchlorophosphate.After removal of the cooling bath, the mixture is treated dropwise at-20° C. to -15° C. with a solution, cooled in an acetone/dry-ice bath,of 2.33 g (21.3 mmol) of potassium tert.butylate and 2.7 ml (21.3 mmol)of ethyl isocyanoacetate in 8 ml of dry dimethylformamide. When thetemperature has reached 20° C., the mixture is neutralised with glacialacetic acid, poured into ca 200 ml of water and left to stand overnight.The separated product is filtered off under suction, washed with waterand dried. After recrystallisation from ethyl acetate, there is obtainedethyl(R,S)-13,13a-dihydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateof melting point 178° C.

EXAMPLE 46

(a) A mixture of 10.0 g of ethyl5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate,200 ml of methanol, 0.5 g of ammonium chloride and 30 g of ammonia(100%) is stirred in an autoclave under nitrogen (40 bar) at atemperature of 120° C. for 12 hours. After cooling and discharging theover-pressure, the mixture is evaporated to dryness. After partition ofthe residue between methylene chloride and water, the organic phase isdried and evaporated. The residue is recrystallised from ethyl acetate,there being obtained5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxamidein the form of white crystals of melting point 274°-275° C.

(b) 0.5 g of5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxamideis heated to reflux while stirring for 40 hours together with 0.5 g ofSicapent in 150 ml of toluene. The mixture is treated with a 0.5 gportion of Sicapent after 16 hours, 19 hours and 24 hours. The mixtureis subsequently cooled and treated with water. The mixture is adjustedto pH 9 with 28 percent sodium hydroxide. After separation of theorganic phase, the alkaline-aqueous phase is extracted twice with 250 mlof ethyl acetate each time. The organic extracts are washed twice withsaturated sodium chloride solution, dried and evaporated. Afterrecrystallisation of the residue from methylene chloride/hexane, thereis recovered a portion of unreacted starting material. The mother liquoris evaporated and chromatographed on 100 g of silica gel while elutingwith ethyl acetate and alcohol. After recrystallisation of thethus-obtained substance from acetone, there is obtained5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carbonitrile of melting point 184°-185° C.

EXAMPLE 47

(a) A mixture of 12.1 g of 5-(trifluoromethyl)isatin, 50 ml of aceticacid and 50 ml of acetic acid anhydride is treated portionwise at atemperature between 80° C. and 90° C. with 10.0 g of chromium trioxide.5 minutes after the last addition, the mixture is cooled to roomtemperature and the separated crystals are filtered off under suctionand washed with water. There is thus obtained 5-(trifluoromethyl)isatoicacid anhydride of melting point 264°-266° C.

(b) A suspension of 5.76 g (24.9 mmol) of 5-(trifluoromethyl)isatoicacid anhydride and 2.44 g (27.4 mmol) of sarcosine in 8 ml of dimethylsulphoxide is stirred at 110° C. for 4 hours, subsequently poured into70 ml of water and evaporated to dryness in vacuo. After columnchromatography on silica gel using ethyl acetate/n-hexane (9:1) for theelution and recrystallisation of the product from ethanol, there isobtained3,4-dihydro-4-methyl-7-(trifluoromethyl)-2H-1,4-benzodiazepine-2,5(1H)-dioneof melting point 203°-206° C.

(c) A solution of 2.36 g (9.1 mmol) of3,4-dihydro-4-methyl-7-(trifluoromethyl)-2H-1,4-benzodiazepine-2,5(1H)-dionein 10 ml of dry dimethylformamide is treated at 5° C. with 1.22 g (10.9mmol) of potassium tert.butylate and at -40° C. dropwise with 1.4 ml(9.5 mmol) of diethylchlorophosphate.

Separately, a solution of 1.12 g (10 mmol) of potassium tert.butylate in5 ml of dry dimethylformamide is treated while cooling in anacetone/dry-ice bath with 1.2 ml (10 mmol) of ethyl isocyanoacetate. Thethus-obtained orange coloured solution is now added dropwise at -20° C.to -10° C. to the mixture obtained according to the preceding paragraph.The cooling bath is removed, the mixture is neutralised after ca 15minutes with glacial acetic acid and the resulting mixture is pouredinto 80 ml of ice/water. The mixture is extracted three times with 60 mlof chloroform each time, the combined chloroform extracts are washedthree times with 60 ml of water each time, dried over magnesium sulphateand evaporated. After column chromatography and recrystallisation of thecrude product from ethyl acetate, there is obtained ethyl5,6-dihydro-5-methyl-6-oxo-8-(trifluoromethyl)-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylateof melting point 179°-180° C.

EXAMPLE A

Tablets containing the following ingredients are manufactured:

    ______________________________________                                                             Per tablet                                               ______________________________________                                        Ethyl (S)-11,12,13,13a-tetrahydro-9-                                          oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]-                                     benzodiazepine-1-carboxylate                                                                         10       mg                                            Lactose                90       mg                                            Maize starch           29       mg                                            Microcrystalline cellulose                                                                           70       mg                                            Magnesium stearate     1        mg                                            Total                  200      mg                                            ______________________________________                                    

EXAMPLE B

Capsules containing the following ingredients are manufactured:

    ______________________________________                                                             Per capsule                                              ______________________________________                                        Ethyl (S)-11,12,13,13a-tetrahydro-9-oxo-                                      9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]-                                         benzodiazepine-1-carboxylate                                                                         10       mg                                            Lactose                165      mg                                            Maize starch           30       mg                                            Talc                   5        mg                                            Total                  210      mg                                            ______________________________________                                    

The ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylate,lactose and maize starch are firstly mixed in a mixer and then in acomminuting machine. The mixture is returned to the mixer, the talc isadded thereto and the resulting mixture is mixed thoroughly. The mixtureis then filled by machine into hard gelatin capsules.

EXAMPLE C

Injection solutions containing the following ingredients aremanufactured:

    ______________________________________                                                             Per ml                                                   ______________________________________                                        Ethyl (S)-11,12,13,13a-tetrahydro-9-oxo-                                      9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]-                                         benzodiazepine-1-carboxylate                                                                         5.0 mg                                                 Benzyl alcohol         0.015 ml                                               Propyleneglycol        0.4 ml                                                 Ethanol (95%)          0.1 ml                                                 Sodium benzoate        48.8 mg                                                Benzoic acid           1.2 mg                                                 Water for injection q.s. ad                                                                          1.0 ml                                                 ______________________________________                                    

For the manufacture of 10,000 ml of injection solution, 50 g of ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5a]pyrrolo[2,1c][1,4]benzodiazepine-1-carboxylateare dissolved in 150 ml of benzyl alcohol and 4000 ml of propyleneglycoland 1000 ml of ethanol are added thereto. Then, 12 g of benzoic acid aredissolved in the foregoing mixture and there is added thereto a solutionof 488 g of sodium benzoate in 300 ml of water for injection. Thesolution obtained is made up to a volume of 10,000 ml by the addition ofwater for injection, filtered and filled into ampoules of suitable size;the residual volume of the ampoules is filled with nitrogen, theampoules are sealed and sterilised for 30 minutes in an autoclave at 0.7atmospheres.

EXAMPLE D

Suppositories containing the following ingredients are manufactured:

    ______________________________________                                                             Per suppository                                          ______________________________________                                        Ethyl (S)-11,12,13,13a-tetrahydro-9-oxo-                                      9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]-                                         benzodiazepine-1-carboxylate                                                                         0.010     g                                            Cocoa butter (melting point 36°-37° C.)                                                1.245     g                                            Carnauba wax           0.045     g                                            Total                  1.3       g                                            ______________________________________                                    

The cocoa butter and Carnauba wax are melted in a glass or steel vessel,mixed thoroughly and cooled to 45° C. There is then added the finelypowdered ethyl(S)-11,12,13,13a-tetrahydro-9-oxo-9H-imidazo[1,5-a]pyrrolo[2,1-c][1,4]benzodiazepine-1-carboxylateand the mixture is stirred until it is completely dispersed. The mixtureis poured into suppository moulds of suitable size and left to cool. Thesuppositories are then removed from the moulds and packed individuallyin wax paper or metal foil.

EXAMPLE E

Capsules containing the following ingredients are manufactured:

    ______________________________________                                                             mg/capsule                                               ______________________________________                                        (+)-5-(o-Chlorophenyl)-1,3-dihydro-3-                                         methyl-7-nitro-2H-1,4-benzodiazepin-                                          2-one                  10.0                                                   Ethyl 8-fluoro-5,6-dihydro-5-methyl-                                          6-oxo-4H-imidazo[1,5-a][1,4]benzo-                                            diazepine-3-carboxylate                                                                              100.0                                                  Lactose (crystalline)  100.0                                                  Maize starch (white)   27.5                                                   Talc                   10.0                                                   Magnesium stearate     2.5                                                    Total                  250.0                                                  ______________________________________                                    

The two active substances are mixed well with the adjuvants and 250.0 mgof the mixture are filled into interlocking capsules of suitable size.

EXAMPLE F

Tablets containing the following ingredients are manufactured:

    ______________________________________                                                             mg/tablet                                                ______________________________________                                        (+)-5-(o-Chlorophenyl)-1,3-dihydro-3-                                         methyl-7-nitro-2H-1,4-benzodiazepin-                                          2-one                  30.0                                                   Ethyl 8-fluoro-5,6-dihydro-5-methyl-                                          6-oxo-4H-imidazo[1,5-a][1,4]benzo-                                            diazepine-3-carboxylate                                                                              30.0                                                   Lactose (powdered)     15.0                                                   Maize starch (white)   19.5                                                   Povidon K30            3.5                                                    Maize starch (white)   10.0                                                   Magnesium stearate     2.0                                                    Total                  110.0                                                  ______________________________________                                    

The two active substances, powdered lactose and the first portion ofwhite maize starch are mixed and sieved. This mixture is moistened witha solution of the Povidon K30 in water, kneaded, granulated, dried andsieved. The second portion of white maize starch and the magnesiumstearate are added to the granulate. After mixing, the mass obtained ispressed to tablets weighing 110 mg.

EXAMPLE G

Tablets containing the following ingredients are manufactured:

    ______________________________________                                                             mg/tablet                                                ______________________________________                                        (+)-5-(o-Chlorophenyl)-1,3-dihydro-3-                                         methyl-7-nitro-2H-1,4-benzodiazepin-                                          2-one                  30                                                     Ethyl 8-fluoro-5,6-dihydro-5-methyl-                                          6-oxo-4H-imidazo[1,5-a][1,4]benzo-                                            diazepine-3-carboxylate                                                                              100                                                    Lactose (powdered)     22                                                     Maize starch (white)   22                                                     Povidon K30            6                                                      Maize starch (white)   16                                                     Magnesium stearate     4                                                      Total                  200                                                    ______________________________________                                    

The two active substances, powdered lactose and the first portion ofwhite maize starch are mixed and sieved. This mixture is moistened witha solution of the Povidon K30 in water, kneaded, granulated, dried andsieved. The second portion of white maize starch and the magnesiumstearate are added to the granulate. After mixing, the mass obtained ispressed to tablets weighing 200 mg.

What is claimed:
 1. A process for the manufacture ##STR31## wherein Atogether with the two carbon atoms denoted as α and β is selected fromthe group consisting of ##STR32## the dotted line represents the doublebond present in groups (a) and (b), D is >C═O or >C═S,R¹ is selectedfrom the group consisting of cyano, lower alkanoyl and a group of theformula --COOR⁴, R⁴ is selected from the group consisting of methyl,ethyl, isopropyl and 2-hydroxyethyl, R⁵ is selected from the groupconsisting of hydrogen, trifluoromethyl and halogen and R⁶ is selectedfrom the group consisting of hydrogen, trifluoromethyl, halogen andlower alkyl and either R² is hydrogen and R³ is hydrogen or lower alkylor R² and R³ together are trimethylene or propylene and the carbon atomdenoted as γ has the S-- or R,S-configuration, ##STR33## wherein A andthe dotted line are as above, R²¹ is hydrogen, R³¹ is lower alkyl andR⁴¹ is methyl, ethyl or isopropyl.